Hi
Version 2.41 (IMHO) generally runs with the least problems but has been superceded by versions 3.10, 3.11 and 3.12 all of which use multiple videotracks which are overlay tracks and the versions have enhanced videoeffects with motion controls. The multiple tracks means more data is saved to the cache file A lot of other features have also been enhanced
The main difficulties reported have been with the speed of rendering the output video, registering editing changes and regenerating the thumbnails which seems to prevent any edits being done until the changes have been saved. This decidedly slows things down compared with 2.41. Naturally, with slower computers this can cause problems. You will have to either download a version and give it a try yourself or have a good look at items on the forum. It's difficult to say which version of these three is the most consistent as people have reported gliches with all three.
Nat