I can't find tooltips anymore!

This morning I started working, just like everyday, on a new model on blender 2.42a (w python 2.4 installed) and I had a bad surprise.
After a while I noticed all the old good yellow tooltips on blender buttons didn’t appear at all! :eek:

So I tried rebooting the pc.
Then I reinstalled blender 2.42a.
Then I uninstalled blender 2.42a and installed blender 2.42a intel optimized, just to test the speed (and, while testing, I noticed neither this version showed me the tooltips!).
Often tooltips help me remember what my little brain can’t remember or give me the right suggestion speeding up my work or teaching me new things in few seconds…!

Somebody can help me make them come back???

P.S. I’ve verified the display option tooltip in view and control is already selected!

Do you see tooltips in other applications that have them?
Have you installed any new software, especially system tweaking-type utilities?

All the other apps that have tooltips work as usual…
And I don’t have any any system tweaking-type utility installed.
I haven’t installed any new software, except the little quick 3d drawing java applications “teddy” and “smooth teddy”. And they don’t require properly to be installed…