To set Firefox to always run in 32 bit mode, open up Finder and go to the Applications folder. Control-click the Firefox app and click "Get Info", then select the "Open in 32-bit mode" option.

Thanks but the only choice is "open with Rosetta"

I just saw you are using Firefox 3.6.16 which only comes in 32 bit. Firefox 4 was the first to have a 64 bit version on the Mac.

I don't know the solution for your problem, you may have to wait for somebody who is more familiar with the Mac, though I don't know of any Mac users who provide regular support on these forums.

OK thanks for the help.

Thanks for your help. It was quite a nuisance (on both computers having upgraded to version 4.) but so easily remedied. Also taught me how/where to find answers, great....Neil