Volker Wiendl has released a new Version of his VsQtAddin Visual Studio Plugin:
Download (Version for VS 2005)
In case you have a previous installed version uninstall it first, and make sure no component is remaining on the system. You may also run
"C:\Programme\Microsoft Visual Studio 8\Common7\IDE\devenv.exe" /resetaddin VsQtAddIn.Connect /Command File.Exit
with your appropriate directory.