Hourglass appears when mouse goes on the app window

[vRltwE]

I am using Qt Creator to do some programming, version 2.4.1 based on Qt 4.7.4 (32 bit). It is presenting a behavior wich I do not understand: When mouse just enters the app window region, the hourglass shows up. In debug mode, a window entitled "Signal reeived" is showed with the following message:

The inferior stopped because it received a signal from the Operating System.

Signal name: SIGSEGV
Signal meaning: Segmentation fault

And Qt Creator shows Disassembler pointing to a line with the following:
0x3c30632c <+0x0000> repnz scas %es:(%edi),%al

Any idea of what is happening? I recorded a video of that, link below.

Thanks in advance.

https://www.youtube.com/watch?feature=player_detailpage&v=Mj43Q_zbe6Y

[S G H]

A Segmentation Fault happens when you Try to Access Memory you Shouldn't access.

An example is:

Accessing the 15th element of a 14-elements array.

[vRltwE]

Thank you EssGeEich.

But that disassembler information may help to find where is the problem?

[S G H]

Nope. Check the call stack if you can. The first function you recognize is the one you are failing.

[vRltwE]

I think call stack isn't there. In the video, I was expecting it to appear at the right side of Qt Creator window. Or am I forgetting anything?

Just adding: Close the project and open a new one, compiling the default code, this behavior persists. Usually, to escape the problem I log off and log in again to Windows XP. Re-open Qt Creator isn't sufficient.