I am expiring the same problem with short empty popup windows that appears in the taskbar and disappers again within a second. They appears exactly every 15 min.
Flipperbw was suggesting that it was his new HP printersoftware that gives the problem. My popups has also started after after installing software for HP PSC 1317 printer. I have managed to take a photo with my digital camera (yes it took me a couple of tries), when the popup occured, and i have attached it .
This shows that it is the HPTSKMGR.exe which executes when the popup appears. I have removed the HP Photo imaging Software, but I still get the empty popups. I didn't remove the "HP PSC & OfficeJet 3.5" and "HP Software Update" because I would like my printer still to work.
Maybe it's the "HP Software Update" program?
Maybe one of you GeekstoGo staff will put a link on flipperbw's topic to this.