Even i have faced same issue. I am using QT 4.5.3 and VS 2005.

And in project properties -

If I change Run time Library to /MT(Multi threaded) it will work but not allowing me to debug code.

If I change Run time Library to /MDd(Multi threaded debug DLL) it will work but crashes in 64 bit machines...

I want to keep option as /MT and at same time want to debug the code..

Can any one help me?