Firefox 3 problem

[samhs]

I've typically got 20+ tabs open at any one time, and that may be related, but recently when opening a link in a new tab, 40% of the time the page loads, then the viewport flicks to all white. A refresh (activated by clicking the refresh button - Apple + R or F5 don't work) fixes the problem as the page loads for a second time it doesn't flick off to white. Has anyone else come across this, found a solution or heard anything about it?

TIA