Hi!

First i will admit that i wrote in C++ and QT a lot of code. Second i don't know English language very good. Anyway, let's focus on problem:
Yesterday all work fine. I wrote some new features all compile and run great. Today i start my project, it compile, start, show windows, and well... that's weird: My click didn't respond correctly. All keyboard functions works ok, but when i click on tabs, or on menu it works first time i click it, but not second. Sometimes works, sometimes don't work. So i can click this or that, but button don't work (even when click enter on keyboard when on button). {so make it clear: GUI functions (like tabs switching) work from time to time, but buttons never} Weird, it's look like function calling don't work?
Well then i quit my program, and try to use other application in QT : like QT Assistant, and i get the same problem. All QT base application stop working.

Ok, so now i think. First what i do: I remove all my system "path" entries -> i leave only system , system32 and QT directory. Then i check to make sure with dependecy walker : It link proper library: C:\Qt\2010.05\qt\bin

Well to keep it clear: i don't reinstall QT or update, this problem start suddenly.

Next step i took was reinstalling QT, but it didn't resolve situation. Probably I can reinstall system to make it work.. but please... it's hours of work.

I didn't make any system restore point, so that way didn't work either.

I search on google and in this forum, but didn't find any useful information.

I consider two options:
1. I have some kind of virus.
2. I install new .dll library in system folder that make problems, or i uninstall needed .dll with some program.

So my question is: Do you have ANY idea why i have such a QT bug? I can post dependency logs or anything you want.

System: XP 32 bits. SP 3. Laptop.