Hi, I'm bumping this post again to ask if it was possible to add
the patch directly to the windows installer, or at least make it available in the game download page... I went through a big part of the game before resolving the issue (lags when casting spells with big sprite that have a lot of transparency, and even sometimes some video driver loss), I began to search a solution when I was stuck to the "witch cutscene" where's lot are used (no spoiler I guess :p)!
Applying the patch resolves the issue totally on my computer (btw win7 / recent nvidia card).
The other graphical bug I had was that characters were "running backward", but I found rapidly that turning the "hardware sprite mirroring" off in the options panel was the solution. No problem with cursor for my part (with and without the patch).
Otherwise, great great game, very stable (only one 'real' crash due to something else than a video driver loss before applying the patch, within hours and hours of game), I recommend it to anyone who does not *know* this rpg!