Eureka!!

[beaky]

Having given up for now on my new video capture card, I went back to getting my mobo to recognize the new CPU. Jus for laughs, I tried Epox's online BIOS tool again, and... connected!! Fell out of my chair!!! Must've tried that a million times before with no success.
Still had to bump up the clock freqs, and I think there may be room for improvement, but now, instead of trying to run FS9 with a 1.2GHz brain with DRAM clock at the default 100, I've now got it going at 1.9 with DRAM at 166, multiplier on "auto" (tried 12x, but POST got hung up on "verifying DMI..." page).
The difference in fps? Many here will not be impressed, but it means the world to me:
Before: with scenery, weather, etc. at about 2/3 the max. settings, fps locked at 29, I was getting about 24 fps average, with fps as low as 9 in dense urban areas, even with default scenery and aircraft.
After: same graphics settings (which look good enough for me, but maybe I'll try sneaking some things up), with fps locked at 50fps, I average about 38, with dense areas still yielding a comfortable 20-30fps.
Woohoo!!
 ;D