PIC16F87 pins seem to be getting crossed over

[The Master]

Ok, Ive made a really basic version to save you looking through hundreds of lines of code. It uses the power LED to show the output (inverted) and the status LED to show the value sent by serial. My laptop sends 1 and 0 alternately.

'^Define_Chip: PIC16F87

'Define the oscillator (20MHz)
DEFINE OSC 20

'Set the tris registers
TRISA=%00001000
TRISB=%11000101

CMCON=7
CVRCON=0
CCP1CON=0

'Serial port settings
RCSTA.7=1	'Enable the serial port
RCSTA.4=1	'Enable synchronous mode
TXSTA.5=1	'Enable transmit
TXSTA.2=1	'Enable high baud rate

'SPBRG=10	'Baud: 115200, Error: -1.36%
SPBRG=64	'Baud: 19200, Error: 0.16%

bTemp VAR BYTE

'Define output pins
pSmoke1 VAR PORTA.2
pSmoke2 VAR PORTA.4
pSmoke3 VAR PORTB.1
pSmoke4 VAR PORTB.3

pPower VAR PORTA.0
pStatus VAR PORTA.1

pData VAR PORTB.4	'Switches between Master and Slave

'Define input pins
iSmoke1 VAR PORTA.3
iSmoke2 VAR PORTB.0
iSmoke3 VAR PORTB.7
iSmoke4 VAR PORTB.6

'Check that input pins are set to inputs
INPUT iSmoke1
INPUT iSmoke2
INPUT iSmoke3
INPUT iSmoke4

'Make sure all of the outputs are off
LOW pSmoke1
LOW pSmoke2
LOW pSmoke3
LOW pSmoke4

LOW pPower
LOW pStatus

LOW pData

'BEGIN: Main loop
loop:
	
	'Check if serial data has arrived
	IF PIR1.5=1 THEN
		
		bTemp=RCREG
		
		pStatus=bTemp.0
	ENDIF
	
	pPower=~iSmoke4
GOTO loop

In this example grounding the input pin makes the power LED light up as expected. When i send the alternating serial values then the status LED toggles as it should. When ground the input _and_ send serial data then the status light never comes on. Something i didnt notice before is that if the status light is already on then grounding the input turns it off. That would suggest that the grounding causes a blank byte to appear in the UART buffer.