speedwalking through any menu

Hello,
Now a strange thing happened with my Cubase 6. If I press a menu button (at start up, or in the top menu bar) the selection “automatically” runs sequentially through all the items at a considerable speed, and I can, at most, get a random choice from all the possible menu items (so it runs through all file items, then all edit items etc.).

I am afraid its a worm or a thing like that, but it is only in Cubase that I encounter it.

Anybody else seen this ?
(and what is a good, thrustworthy worm etc. finder and killer ?)

regards,
Gerard

(Vista ultimate 64 bit, ASUS P5Q Pro, RME HDSP, 8 Gb)