Info panel not showing or frozen

Hi all, I’ve had Blender installed for a couple of years but never used really. I was impressed by the 2.5 features so I though it was time to move to blender (I’m not a 3d artist, I’m a programmer :-).
I was able to run it a few times, but now the ‘info’ panel (the one with the file and render items) is completely black or frozen, and I cannot work.
Any idea about how to fix it?
Thank you!

I noticed that this happens when I load my saved file. I tried by creating a new scene, then it worked until the first render. Just after activating the ‘default’ view again it stopped working.