Very slow game speed Options

[Shadan]

I am planning to play an another BG2 run while we are wating for v6 release, but I have one serious problem. In all of my BG2 games (was 3 of them with IA) I experienced a very slow game speed in certain situations.
1. When there were lot of enemies and/or corpses on the screen (like githayanki suprem leader fight).
2. When there were many spellanimation on the screen (like SI, Mirror Image, GoI, Spell Turning etc.).
3. When I fought against big monsters (like any dragon).

It was very frustrating sometimes. First I thought it is because I have some mods (like bottomless Bag of Holding), but later I had only IA and The Four installed after ToB patch, Baldurash and EoU, and I dind't have bottomless Bag of Holding at this time. Despite this clean and modfree IA install, I had very slow battles still. My computer is not the newest, but I have 2 giga memory and I can play all games, even WoW without any difficulty. Can anyone give some advices how can I avoid this slow speed in BG2?
Ah, I played in 1024*768 resolution, but I tried in 800*600 also to check if this could be a problem.

[Raven]

Hmm I have played IA for a long time on a far worse computer performance-wise and I haven't noticed any bad slow down. Have you tried the steps mentioned in the FAQ page:

1- Make sure that you have followed the mod's installation instructions accurately. In particular, make sure that you have NOT installed BG2 TweakPack.

2- Make sure that you don't have a bottomless bag of holding. (Also, make sure that you have not installed any other mod which adds new containers (bags, etc) to the game.)

3- Make sure that the 3d acceleration option is not turned on in your game's configuration.

4- Make sure that you have made a clean installation of the game before installing your current mods. Leftovers of old mods (even after uninstalling them) may cause such problems.

5- Make sure that a "Real Time Virus Protection" is not running in the background on your machine.

6- Make sure that your machine (if an old one) is not continuously running for more than 12 hours without a restart. A restart will help the machine to refresh its resources.

7- Make sure that the hard disk has at least 15% free space (both the directory in which windows is installed and the directory in which BG2 is installed).

8- Defragment your computer.