Not yet...these are the supported FXs from those 45.23 drivers...
GeForce FX 5900
GeForce FX 5900 Ultra
Quadro FX 3000 NV35
GeForce FX 5200 Ultra
GeForce FX 5200
Quadro FX 500 NV34
GeForce FX 5600 Ultra
GeForce FX 5600
GeForce FX 5600 SE
NV31
GeForce FX 5800 Ultra
GeForce FX 5800
Quadro FX 2000
Quadro FX 1000
How in the world...? The FX 5500 must have been one of those "Hey, we'll go back and release another FX series graphics card and just stick in there somewhere... FX 5500 sounds good!!" 
I'll keep looking.
(I just LOVE how some of the drivers descriptions on some sites -Guru3d- say "All NVIDIA cards are supported". What a joke.
)
Something that would be very handy: Does anyone know of a way to find out what drivers were released with what card? I know that's a little vague, and it's such a dynamic thing, but it would be nice to know when a card was manufactured (approximately) without having to pull one and read the S/N off it, then search a website's help section to see what they all mean. It would be nice to find out when, say, an FX 5500 was "released" so the appropriate driver for that release would be easy to find. Just a thought.
Or, what drivers were released with your card...like if you could find the CD with the drivers on it, which I can't. I need to get organized..with a Capital 'O'!!
At the moment, I'm all the way up to v53.04 and NO FX5500 support...still looking.
Allright, I got my FX 5500 working with 56.64 drivers and it looks pretty good. We needs us some comparison screenies. Something easy to get to, or those places in Lord Alan's Fortress? You decide. (Just in case you don't see this, I'm going to go poking around in Lord Alan's Fortress. I can't wait.