What configs are you using? If it is the default ones in pbp/18f2450.inc then they are set to:

Code:
        __CONFIG    _CONFIG1L, _PLLDIV_5_1L & _CPUDIV_OSC1_PLL2_1L & _USBDIV_2_1L
        __CONFIG    _CONFIG1H, _FOSC_HSPLL_HS_1H & _FCMEN_OFF_1H & _IESO_OFF_1H
        __CONFIG    _CONFIG2H, _WDT_ON_2H & _WDTPS_512_2H
        __CONFIG    _CONFIG3H,_PBADEN_OFF_3H & _LPT1OSC_OFF_3H & _MCLRE_ON_3H
        __CONFIG    _CONFIG4L, _STVREN_ON_4L & _LVP_OFF_4L & _BBSIZ_BB1K_4L & _XINST_OFF_4L
That should get you 48 mhz instead of 20 mhz.

And for the hardware, do you have the 3.3 volt jumper on, or off?

Can you get the chip to blink an LED or something to make sure its running?

If you decide to go with hardware uart here are some defines for 48 mhz.

'DEFINE HSER_RCSTA 90h ' Enable serial port & continuous receive
'DEFINE HSER_TXSTA 20h ' Enable transmit, BRGH = 0
'DEFINE HSER_SPBRG 77 ' 9600 Baud @ 48MHz, 0.16%
'DEFINE HSER_CLROERR 1 ' Clear overflow automatically