Can't say I've ever had them stop working, but I've had lots of problems graphics wise. A few seem to just jutter their way along, merrily ignoring the rest of the world.
One thing that surprises me is how some games that are ten or so years old, actually have the options for big resolutions - for example, Populous: The Beginning and Ghost Recon seem to be able to go up to the 1600s.
I'd imagine that a lot of games would have trouble running on Vista, though.
By the way, I found a couple downloads for packaged Fallout 1 and Fallout 2 combined, not legal but if you know where to look they're super easy to find(and have lots of seeders too(hint))
That's probably the one I, ahem, didn't download on Friday in a couple of hours. It isn't 1.09gb, by any chance, is it? Because that's definitely not the one I, ahem, acquired.
Well there's "Fallout; The Ultimate Collection" which is 3.49 Gigs, but I also see the one you're talking about which is simply just Fallout 1 and Fallout 2 that is 1.09 Gigs. Not sure what exactly the Ultimate Collection is, probably Fallout: Tactics or whatever else they have.