For about a year I've been getting the whirling, multi-colored beachball on my MacBook. This only happens when I am using Firefox. If I use Safari, the browser which came with the machine I can get through my session with no problems.
I have updated Firefox constantly throughout the entire time. All of my bookmarks and preferences are synced in Firefox with my older PC machines. When I fire up one of my older PC laptops, Firefox functions flawlessly. The lockup only happens in Mac. The rainbow globe goes on forever and I have to shut the computer down by holding the power button down until it shuts.
I bought something called "Mac Keeper Pro" which supposedly cleans a Mac but it does not help with Firefox.
Has anyone else had this happen?