Scrnsaver exits with Blank On Taskbar

Using A-Trend ATC-7460M motherboards with Celeron 433, 64MB RAM in a Peer to peer network and a Chaintech CT5SSV motherboard with a K2-400, 64MB RAM in a standalone system all running Win98SE. On exiting a screensaver, any screensaver, a Button devoid of text is left on the taskbar on coming out of the screensaver and a further button is left every time they come out of screensaver. They can be cleared by simply clicking on the blank button, if this is not done they keep adding blank buttons to the taskbar. The standlone unit has all the latest downloads from both Microsoft and Chaintech. With Win98SE the only common ground anybody know the cause.