Hi from France, and sorry for my english...
I've got this same problem ; can't run SL since 6 months, but previously was working fine on my Windows 7 premium 64bits SP1.
I think effectively this problem is behind my GE Force GT240, i've accepted an automatic update from Nvidia ; i dont know if it came at the same time, but can be true, about 6 months ago.
Tried the Second_Life_3-2-2-245264_Developer_Setup, but no difference for me.
I'm frozen with that joke ! No SL since months !
I'll follow if an answer appears, but i'll leave if i cant find a solution.
Thx for your help, pleasure.
Harvey