QT Release build DLL procedure entry point error

Even if the library version is the same they may be non compatible. For instance they were compiled with different configurations, like with or without STL support, OpenGL, SQL drivers...

The simplest way to fix it should be to move Qt SDK's path at beginning of PATH environment variable. This way whenever you run an executable that requires Qt libraries it will load the ones shipped with SDK (the first ones found in PATH), unless there are already copies of QtCore4.dll, QtGui4.dll... in the executable's directory. For this reason if you redistribute your application you might also have to ship the libraries in its directory.

Another option is static linking, but you will be required to provide source code under the (L)GPL licence.