Qt 4.7.1 libgles_cm.lib for OpenGL ES can't be opened

Hey everybody,
first: I actually posted this question in an other subforum of Qt Centre as well (Qt-Programming), which obviously was wrong. Sorry about that.
My Problem: Since I installed the new Version of Qt (4.7.1) my linker complains, that the file libgles_cm.lib cannot be opened. This somehow relates to OpenGL ES, which I don't use and don't need. With the previous Version (4.6.x) I didn't have that problem. Can I deactivate OpenGL ES in Qt, do I have to install something else to obtain this files?
thx

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Added after 1 50 minutes:

Ok, I found the solution myself. The Problem lies in Visual Studio Projects that have been created with a previous version of Qt. After just loading all of my files (without altering them) into a new folder and adding them to a new VS QT4 Project everything worked fine.
Daniel