safari won't scroll down the page
I have had a recurring problem where I will open a web page in Safari and it will load completely. Then it will not let me scroll down the page - I can see only what is on the first screen. Reloading the page does not work. If multiple tabs are open, other tabs will be working fine - but one tab will not.
I have to shut Safari down and re-open it in order to load the page.
This has been going on for several weeks and I have yet to see a Software Update that fixes this problem. Others seem to have the same problem - but I'm not a high-level techie and I don't want to be doing absurdly technical things to fix this.
Can someone tell me what the problem is and how I go about fixing it?
I have Lion running on iMac.
iMac, Mac OS X (10.7.2)