My PC is running the following:
Windows 7 - Dual Core - 64 Bit
Firefox.exe *32 - version 5.0
This problem has only started occurring since my latest upgrade and I narrowed it down to Firebug by disabling each plugin one by one.
When I now click the link the popup opens full size rather than the dimensions set 400px * 400px and there is nothing on the page - just a blank screen. Viewing the source shows nothing at all.
This page used to work fine before the update.
It still works on all other browsers Chrome, Safari, IE (6 to 9) and it still works in Firefox 5.0 on 32 bit machines so I am not sure whether it's a 64 bit problem or not.
Viewing my Task Manager window I can open Firefox and I can get my Firefox to use beyond 1GB of memory and 50% CPU (the whole of one of my two processors) with only one single window and tab open all within 5 minutes.
Earlier today it was using over 3GB of memory!
Another clue is the fact that the error console is permanently full of these error messages:
attempt to run compile-and-go on a cleared scope
Hitting clear just fills up the whole of Firebug's console log instantly with the same message.
The only way I have found to solve this problem is to disable Firebug and not use the "Restart Firefox" link as this seems to just ramp the memory up without shutting the process down first.
I usually have to kill the process through Task Manager as clicking the close button doesn't do anything the majority of the time.
If anyone else has similar problems please let me know.