*sigh* Problem fixed, and it was in fact a faulty board.
After working for a month with software with no success, I finally broke down and tore the machine apart and stripped/swapped parts with another machine. Threw in an old GF2 MX I had available, and everything immediately worked.
So, after very close inspection of my PNY Verto GF4-4200 Ti 64Mb, I found corrosion around the solder joints of two of the eight capacitors on the board ... they looked like old alkaline batteries that had exploded and leaked battery acid. As I indicated previously though, whatever hardware functions these capacitors supported was only present with nVidia's drivers, not the XFree default nv driver.
I was able to get a very courteous Best Buy tech to replace the board, despite that BB's policy is normally only 30 days, and the board was approx 6 months old. Notably though, PNY's RMA staff was especially NON-helpful.
What I want to point out for other owners of PNY's boards though, is that my original board had other capacitors that were abnormally bulged or deformed, which implies they might have been defective from manufacture. The replacement board I received (EXACT same listed model, documentation and box) was in fact substantially different - it was silk screened in aqua blue as opposed to purple, and the layout, manufacturer and voltage ratings of the capacitors were significantly different, despite that the board serial numbers were the same. The cooling fan on the GPU was also of different manufacture and is now made of aluminum instead of plastic, so it doubles as a heat sink across half the length of the board.
I've scoured the web and have not found any info as to whether the first-gen Ti's produced by PNY were formally recalled, but it would appear to me that PNY is aware that there was a problem with their original hardware (or at least their component supplier's hardware).
I've been very happy with all the hardware I've ever purchased from PNY over the past several years, it's always been cost competitive and very reliable, and I am not trying to propogate any conspiracy theories, but as they say ... buyer beware.
- Rich B
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