Revit 2010 WU2 sometimes fails to start?!

Revit 2010 WU2 x64 sometimes fails to start?!

My setup is Windows 7 Ultimate (MSDN)
Revit 2010 + WU1 +WU2 x64 (latest version)

Sometimes when i launch the program i just keeps on loading displays the window but never finishes. Just stays there doing nothing.

I've managed to "see" that when i look in the bottom left corner and is says "License is no expiring etc..." then it finishes starting 100%.

Sometimes it does not display that message and it never finishes starting.

Is there something wrong, or something i have to do with the license?! I'm a standalone installation.

Also... trying to start two revit sessions at the same time results in both of them not starting... this does not happen in autocad.