have you tried building from the Qt command prompt?
Show compile output (inside Qt Creator) from both of these projects just after a Clean-all.

I noticed the folder name 2009.05_new - is that the standard location?
I am not suggesting this is happening to you, but I once had some weirdness due to having multiple MS compilers (VC++ express 2008, VB express and an old visual studio etc) installed. Only after removing all these and the platform sdk I was able to get it working again.

[ducks] or you could try to reinstall Qt