Keith,
OK, I have now tried to program my 18F2431 with the resistor only (no caps) fitted between pin 7 and 11 which is AVdd and RC0/T1OSO/T1CKI on the 28pin parts and I'm happy to report that it works - at least here. I also managed to get the QEI module counting my quadrature encoder, yes....

I added the labels (AVdd & RC0) in my original post because I thought it was strange and I didn't understand what it was supposed to do there. Perhaps it is as as you say that when programming a 2431 power is applied to pin 11 (which is power for 4431) instead of pin 7 and the resistor feeds it to pin 7. But then again, why doesn't your 4431 program? To bad I don't have any to test with, sorry.

Let us know what you find.

/Henrik Olsson.