TMR0 overflow problem

[skimask]

And where might I find the "config options" file?

Sorry...I thought I typed more in there Don't know what happened. I'll blame it on Windows
Umm....config options...stand by for further edit...

Ok, when I need to know what my actual config options are, as defined by the assembler, MPASM (because the compiler, PBP, could generally care less what your config options are), mine are located at:
C:\Program Files\Microchip\MPASM Suite\
And in your case it would be the:
P18F1220.INC file, way down at the bottom of the file. Paste those options into the PBP INC file as described by the above link and you should be good to go.
OR, as described by the link above, you can comment out all of the config options in the PBP INC file, and paste them as one line assembly lines into your main program.
Personally, I almost always use the same config options for each style of chip, therefore, I comment out the 'stock' config options in the PBP INC file for the chip I'm using, and paste in the config options that I always want, as described in the link above. That way, every time I use a particular chip, I'm always configuring it the same way, every time, no surprises. If I go to a different chip, I modify PBP's INC file for that chip, and do it the same way, as described in the link above.

[jderson]

Thank you for your help. I found the file, and I will add them to my program (in the proper manner) tomorrow. I still wonder why PBP does not support this device, when the sales literature says it does. (Not that it matters for the problem I'm having!)

[skimask]

Thank you for your help. I found the file, and I will add them to my program (in the proper manner) tomorrow. I still wonder why PBP does not support this device, when the sales literature says it does. (Not that it matters for the problem I'm having!)

It does support it. It has since PBP 2.43, a LONG time ago.
Changing the config options isn't something new (look at the date on the post of the aforementioned link). PBP doesn't handle config options (it can, but that's not it's job), that's the assembler's job.