When I was a Leicester University, there was a Cheesy Funk society, dedicated to the best, and worst '70s and '80s music. I only bring this up because I got Vice City working again last night, and this game would be their soundtrack.
It appears that the reason the game wouldn't run properly was because I'd ported over my previous save games from a backup CD to the My Documents directory, so when the game tried to create the Vice City user files directory, it simply bombed out because it couldn't create something that already existed. I'm sure this is probably the same problem I had with GTAIII, too.
So, only the install problems with Operation Flashpoint to solve now.
In the meantime, to salve my soldiering itch, I'm playing Project IGI again. The game suffers a little from the first time through the level being ultra-hard, but once you've figured out how to beat the level, it's a piece of cake on subsequent replays. However, this still doesn't stop it from being very, very good. The weapons are excellently modelled - the Pancor Jackhammer in particular packs a suitably vicious punch. And it's now out for a fiver - well worth the money if you've not played it.