That really surprises me, the 2940 was a dirt common card.
Maybe this would fix the problem? (It sounds like there's some motherboard incompatibility... thing?, maybe? that crops up with that card? I used a 2940UW in my AMD Tbird box (the one built using that K7 motherboard you mentioned having) and it always worked flawlessly for everything I asked it to do. Granted, the one thing it never was was the boot drive. (I used it to drive the scanner and to do weird hackery with drives from non-PC systems.)
Another reference to the same bug?