I have an X stuck on my desktop

[Mark Kirven]

Everytime I boot I have an X, which is dead center of the desktop,
stuck there. It appears where the cursor appears after boot, it stays
on top of every window or app opened. If I open any window or app and
simply click one time on the title bar the X goes away.
I was curious if anyone else is having this problem and how to get
around it. I am using a Compaq Presario 700. Thanks in advance.