What’s more funny is when we looked at our screen, the windows resizes incrementally (going larger or going smaller, again without any command issued by way of a mouse click). It’s like this version has a mind of its own, we said to each other (this author and other users).
I have unchecked the Move or Resize Existing Windows option and Firefox 3.5.1 started to behave “normally”. If you have experienced the same problem, try the solution we’ve found by accident. The latest FF version still needs some improvements. We will update you on this and give our report on its RAM and CPU usage.