After upgrading to Firefox 9 I find that there is a problem using it with Gmail. When I am typing a Gmail message, and I hit the back space repeatedly the whole Browser window goes white and hangs for about 5 seconds. This does not happen in Chrome or Internet Explorer.
This is a problem because I use a spell check program called As U Type. To make a correction it backs up and retypes the word. but Firefox screws this process up.
I am using a Windows 7 64 bit machine with several monitors.