I went through the datasheet again, and again.
I also went through Microchips MRF Radiodriver software source code, link here.

Here is what I put together, see if this helps at all.......

Code:
     RF_Init_Values[0] = $28                                                   'Standby mode, 915-928 MHz, VTune by inductors, ENABLE R1/P1/S1
     RF_Init_Values[1] = $8C                                                   'FSK, max IF gain, Packet Mode
     RF_Init_Values[2] = $0B                                                   'Change from 200KHz Freq Dev to 33KHz Dev
     RF_Init_Values[3] = $63                                                   '2KBps
     RF_Init_Values[4] = $0C                                                   'for OOK mode, not apliable
     RF_Init_Values[5] = $03                                                   '16Bytes FIFO, 3 Bytes threshold FIFO transmit interrupt
     RF_Init_Values[6] = $77                                                   '915MHz R1 Reg
     RF_Init_Values[7] = $64                                                   '915MHz P1 Reg
     RF_Init_Values[8] = $32                                                   '915MHz S1 Reg
     RF_Init_Values[9] = $74                                                   '920MHz R2 Reg
     RF_Init_Values[10] = $62                                                  '920MHz P2 Reg
     RF_Init_Values[11] = $32                                                  '920MHz S2 Reg
     RF_Init_Values[12] = $38                                                  'config mode for OOK, not apliable
     RF_Init_Values[13] = $08                                                  'PLREADY, CRCOK, TXDONE, FIFO Not Full, FIFO Empty, No FIFO Overrun
                                                                               'TX: mostly normal
     RF_Init_Values[14] = $0B                                                  '00111001
     RF_Init_Values[15] = $00                                                  '
     RF_Init_Values[16] = $41                                                  'default filters config
     RF_Init_Values[17] = $38                                                  'default filters config
     RF_Init_Values[18] = $30                                                  'sync word ON, 24bits, 0 errors tolerance
     RF_Init_Values[19] = $07                                                  'reserved reg
     RF_Init_Values[20] = $00                                                  'RSII status read register, 0.5dB / bit
     RF_Init_Values[21] = $00                                                  'OOK config reg
     RF_Init_Values[22] = $53                                                  '"S" 1st byte of sync word
     RF_Init_Values[23] = $43                                                  '"C" 2nd byte of sync word
     RF_Init_Values[24] = $53                                                  '"S" 3rd byte of sync word  - my initials!
     RF_Init_Values[25] = $00                                                  '
     RF_Init_Values[26] = $F0                                                  'utoff fcy = 200KHz, output power = 13dBm 0b000
     RF_Init_Values[27] = $80                                                  'clk out by default 427KHz
     RF_Init_Values[28] = $03                                                  '3 bytes payload
     RF_Init_Values[29] = $01                                                  'initial MAC ADDRESS, only for test
     RF_Init_Values[30] = $4E                                                  'Fix Packet Lenght, 3 bytes preamble, whitening ON, CRC ON, Node ADDR|0x00|0xFF filtering
     RF_Init_Values[31] = $00                                                  'FIFO autocreal enable if CRC fails, Write to FIFO in stby mode     for (i = 0; i < 32; i++)
    
RF_STANDBY     con $20      'Standby RF Mode     
RF_SYNTHESIZER con $40      'Synthesizer Mode (Test if RF Module is on and PLL Locked and working)
RF_RECEIVER    con $60      'Receive Mode
RF_TRANSMITTER con $80      'Transmit Mode

TxPacket var byte[16]   'Packet Buffer
bRF_Mode var byte       'Used to set RF Mode
RF_Mode var byte
wr_FIFO_Val var byte    'byte to load into RF FIFO
bReg_Address var byte   'byte for which register to set/read
bReg_Value var byte     'Value of register to set/read
TxPacketLen var byte    'Number of bytes to send
i var byte    
PLL_LOCK var bit        'Bit to read PLL Lock Flag


TestMe:
    gosub MRFInint
    TxPacket[0] = $A1
    TxPacket[1] = $B1
    TxPacket[2] = $C1
    TxPacketLen = 3
    gosub Send_Packet
    bRF_Mode = RF_STANDBY
    gosub SetRFMode

    goto RCV    'This is a jump to your receive routine
    
MRFInit:
'Initialize the MRF Module
    'Intial setup
    for i = 0 to 31
        bReg_Address = i
        bReg_Value = RF_Init_Values(i)
        gosub RegisterSet    
    next i

    'Test the module setup
    'Clear the PLL Lock flag by setting LSTLPLL to 1
    bReg_Address = $0E  'FTPRIREG
    gosub RegisterRead
    bReg_Value = bReg_Value | $02   'Set LSTLPLL to 1
    gosub RegisterSet   'Clear the flag
    
    'Enable Synthesizer mode and test LSTSPLL stays at 1 (PLL Locked)
    bRF_Mode = RF_SYNTHESIZER
    gosub SetRFMode

    'Verify PLL Lock Flag
    bReg_Address = $0E  'FTPRIREG
    gosub RegisterRead
    PLL_LOCK = 0
    PLL_LOCK = bReg_Value.1
    'You can test this bit to see if PLL Is Locked
    
    'Change to Standby  
    bRF_Mode = RF_STANDBY
    gosub SetRFMode
    
    return

Send_Packet:
    
    'Set Standby mode
    bRF_Mode = RF_STANDBY
    gosub SetRFMode
    
    'Enable FIFO access in Standby mode
    bReg_Address = $1F  'Register 31
    bReg_Value = (RF_Init_Values(bReg_Address) & $BF) | $00
    gosub RegisterSet
    
    'Clear FIFO Overrun
    bReg_Address = $0D  'Register 13
    bReg_Value = (RF_Init_Values(bReg_Address) | $01)
    gosub RegisterSet
    
    'Set PLL Locked
    bReg_Address = $0E  'Register 13
    bReg_Value = (RF_Init_Values(bReg_Address) | $02)
    gosub RegisterSet
    
    For i = 0 to (TxPacketLen-1)
        'Wite the Packets to the FIFO
        wr_FIFO_Val = TxPacket[i]
        gosub WriteFIFO
    Next i 
   
    'Set RFMode to Transmit
    bRF_Mode = RF_TRANSMITTER
    gosub SetRFMode
    pause 5 'Pause 5ms
    
    return
        
WriteFIFO:
'Inputs: wr_FIFO_Val
    
    MRFDataSel=0                
    SHIFTOUT SDO, SCLK, 1,[wr_FIFO_Val] 
    MRFDataSel=1                

    return
    
SetRFMode:
' Inputs bRF_Mode
    'SetRFMode(RF_STANDBY); (mcparam0_read & 0x1F) | RF_STANDBY) = (6E & 1F) | 20 = 2E
    bReg_Address = $00  'MCPARAM0
    gosub RegisterRead
    mcparam0_read = bReg_Value
    bReg_Value = (bReg_Value & $1F) | bRF_Mode
    bReg_Address = $00
    gosub RegisterSet
    RF_Mode = bRF_Mode


    return
    
    
    
RegisterSet:
'Inputs: bReg_Address, bReg_Value
    MRFaddr=(bReg_Address<<1)                                           'Gets register address format
    MRFConfigSel=0                                                      'Select the chip
    SHIFTOUT SDO, SCLK, 1,[MRFaddr,bReg_Value]                          'Set the register
    MRFConfigSel=1                                                      'Deselect the chip
 
    
    return
    
RegisterRead:
'Inputs: bReg_Address
'Outputs: bReg_Value
    
    MRFaddr = ((bReg_Address << 1) | $40)               'Shifts left 1 bit, sets $40 bit, automatically gets start, READ, and stop bits         
    MRFConfigSel = 0                                    'Select the chip
    SHIFTOUT SDO, SCLK, 1,[MRFaddr]                     'Address to read
    SHIFTIN SDI, SCLK, 0,[bReg_Value]                   'Get data from reg
    MRFConfigSel = 1                                    'DeSelect the chip
    
    return