Random program starts up then disapears

[fire_munki]

When windows is running along nicely with what ever I'm playing/doing regularly a little blank program box turns up on the taskbar. If i'm in a game it puts me back to windows but then disapears. I've run a very up to date Kaspersky virus check, and a Lavasoft Ad-Aware but neither found anything.
Can anybody help me?

[fry]

Try to scan your computer for viruses and spywear in the internet.
RAV Antivirus Online Scan
Free online Spyware Checker - as far as i know, it has the biggest base of spyware.