Hi Hrvoje, have you contacted us about this recently? I can see a support ticket regarding similar issue submitted by you, but the last message is from 5 months ago. You are right, currently the replies may come a bit delayed, that's because we received a lot of tickets and questions after the 1.5 release - which is actually good, because it indicates how much interest there is in Corona.
As to the issue itself - this is often very hard to diagnose. Could you provide us with a sample scene where this happens, or at least a good description of the scene and the problem itself? What exactly are you doing, and what is happening?