I have the 1.4 patch . Game is from GOG. I have the same problem described in the attached post. Anyone else? Any solutions? Thanks

http://forum.baldursgate.com/discussion/8036/slow-response-to-mouse-clicks-mouse-lag

Playing single player. Tried re installing twice. Seems to start ok and get worse as I play. Any help?

Try toggling the hardware cursor in graphic options. It may be a compatibility issue.

Thanks - already tried that. It's weird because the game runs fine for up to the first hour or so, then it gets worse and worse.

If it's happening after a period of play, have you tried rebooting your computer? Also don't play with other applications running in the background, and temporarily disable any antivirus you have while playing. Something on your system (hardware or software) is likely the cause if it gets worse over time.

Isn't this the same engine as in Baldurs Gate EE? I have that - although through Steam - and I have no issues.

It's the same core engine, yes, and GOG or Steam makes no difference, it's the same game.

Care to elucidate?

I mean if they both use the same engine, why would one game work fine and the other give me problems? Weird

They may use the same engine, but IWD:EE is not BG:EE; different coding. But without knowing your specific system, I'm not convinced it's the game, else plenty of other people would be complaining of the same issue. It could be something on your system that this specific game chokes on, which seems highly possible. You could always ask at the EE forums.