Read the newbee threads, 16F877A no go.

[NavMicroSystems]

Hi,
>DEFINE OSC 11 is an illegal setting.

Where does any documentation say that ?

I probably would have noticed if somewhere it said:
THE ONLY ACCEPTABLE CLOCK SPEEDS ARE, 3(3.58) 4 8 10 12 16 20 24 25 32 33 40

See PBP Manual Appendix B "Defines"

EDIT:
ok, Steve was faster (as most of the time)