Qt 4.3 incompatible with .NET framework 2.0 servicepack?

I have installed winxp 64 with .NET framework 2.0,3.0,1.1 and VS 2005+sp1+hotfix(qhash) and Qt 4.3.3 .
Everthing is running well. But if a install the serviepack fro .NET framework am not able to start VS 2005.
The splashscreen is shown for a few seconds and than nothing is happen.
Maybe this is not a problem Qt.
But now i have setup a new computer. I have installed winxp 64 with all servicepacks and updates(including .NET framework 2.0,3.0+servicepacks).
VS2005 (+sp1, without hotfix) is running well. But i am not able to install the qt vs integration. Some dlls are not able to be registered.
I am also not able to compile Qt 4.3.3. I have started the compilation several times and it stops at different points.

Could it be that Qt 4.3.3 is incompatible with .Net framework 2.0 servicepack?

No, it is more likely because of the platform(64bit).
Qt hasn't much to do with .NET.

What errors do you get?

I do not think it's a problem with 64bit. I am working with winxp 64 for more than one year without any problems(qt compilation+qt vs integration).
The problems start with .Net framework 2.0 servicepack.

I got the errors:
Can not register QtProjectEngine.dll
Can not register formeditor.dll
Can not register qt4v.help
Cannot register qt help

On the new computer i have solved the problem.
It was a problem with Kaspersky Internet Security 7.0. If i had deactiviated it i was able to install the vs integration.
The problem with my old computer still exists.