Page Dropping

[chiglet]

During the past week or so, I have had a problem of "page drop"....eg, I am on Pprune Rumours and News. I click on the Item at the top of the page...and Pprune vanishes. Get back in, and every now and again, it drops out. [Not only with Pprune, other applications as well (eBay..eg) ] Any help would be appreciated.
watp,iktch
The page/Pprune dropped as I hit the "Submit" button....HEEeellllp