I've installed BG:SOA:TOB with the mods The DArkest Day, Freedom's Reign and Reign of Virtue and the XP-cap remover.

Before the mods the game ran like a charm. Now it crashes every time I quicksave (of which I was warned in Dan Simpsons' walkthrough, so I could live with it, even though the game never crashed without the mods, but the worst is that it also crashes half the time it autosaves or when I just save the game. It also crashes sometimes when I start up or try to open a saved game. I'm becoming very frustrated by this.

Is there anything I can do to make it work properly again?

Unfortunately, TDD is fairly buggy. While I can't say for sure, I would guess that it is likely causing the problems.

Crashes on saving and loading can also be caused by a corrupted image file in a saved game. Try moving all your saved game files out of the saved game directory and then saving a new game. If that works, bring back one of your saved games and see if you can load it. In my experience, usually it is the auto or the quick save that gets corrupted. If this is the problem, you can restore all the saved games except for the one with the corrupted image.

I doubt that TDD is causing this one.

You shouldn't install an XP-Cap Remover with any mods. I highly doubt that TDD, FR, and RoV are compatible with each other. Most likely its the combination of what you've got installed that's causing the problem.

There is one thing you can do yes. Don’t install any mods. They are not worth the aggravation.

Well, let me same you some trouble later on. Uninstall TDD. It may ruin your life.

TDD is buggy, but I never had *that* bug with it. But I have had corrupted images in saved games that have caused the same problem even in unmodded installations.