Greetings, Pazy!
Second Life has been working fine for me since ATI released the Catalyst version 7.3 drivers back in March (they are up to Catalyst version 7.7 now). From what I’ve heard, in general folks running Vista have been doing fine since the Catalyst 7.3 release. I have an ATI Radeon X1950XTX and am running the 64 bit version of Vista.
You might have some problems, however, with the Radeon Xpress 200- that’s a somewhat older video chipset in a laptop if I’m not mistaken. I’m not sure if that will support the necessary video features that Second Life requires.