Skillster's right about needing to force the AA on.
You see, in most cases Voodoo5 5500 you had, didn't have a "let the software select" option for the AA (to my knowledge, that is....and yes, I'm running a V5 5500 AGP, and that's been my experience regarding AA support in drivers). It was either forced on or forced off....which at the time was good, as it allowed the FSAA to work on older games which didn't have the ability to select the AA mode. (Possible boon from this: FSAA could work in FF7pc without needing to be patched....I can't test this on my V5, as FF7 seems to be having problems with the Truemotion Video codec, thus crashing before I can even get to the game)
Nowadays, FSAA support is standard in all mainstream 3D cards, and as a result most games have some sort of support for selecting the AA mode, which justifies having a "software select" setting for the card.