mouse pointer blinks/disappears while surfing

Hi. like the title says, my mouse pointer blinks and disappears while visiting certain sites. the mouse in question is a logitech mx1000 laser mouse. when on the desktop or in the windows explorer i have no problems. but when i'm surfing the web, the problems start. sites where i have problems are Photobucket, Yahoomail, and some other commonly popular sites. i never had a problem before, this must have just started within the month. i must also note this occurs regardless if i use IE Explorer 8 or Firefox 3.0.5-please help me out. thanks. my operating system is windows xp pro/sp3. looking forward to some replys

Have you tried using a different mouse? I know, it is most likely a software issue since it's on the screen, but may as well give it a shot. Have you also tried clearing your internet caches?