Ah, thanks Troy! I didn't run a search in other forums for the problem, just the bug reports forum. Interesting, at least I am not alone with this!
A little more information in case it helps at all in figuring out what triggers it.
Computer Specs:
Windows XP with Service Pack 2
Intel P4 3.0 GHz with 2GB RAM
This computer is about 3 or 4 years old now.. heh, probably should upgrade it soon.
I only use FireFox, so I can't say if it would be any better in IE.. IE scares me.
I tend to have several tabs open in one session, maybe that's the cause? Around 7 which are mandatory and then 2-3 more for doing research or any other activities. I don't experience any lag or anything while switching tabs. I usually only have 4 other programs running... such as Thunderbird, shell window, editpad, and a live chat program (provide support).
I really don't think that it is a problem with how many programs or tabs that are open since I never experienced this problem before and I've always been a multi-tasker. I think it might be the code in WHMCS itself (as noted in that other thread, the AJAX code).
What happens when it crashes the browser? After I click "Add Response" my window will go completely blank (white screen) and the FireFox browser will become unresponsive. I have to open the Task Manager to manually kill the program sometimes, other times FireFox just closes itself.
Restoring the session opens up all the tabs (can be annoying to re-authenticate master passwords and then all the tabs that have passwords!) and the WHMCS tab shows the response I submitted as being successful and listed under the ticket. I actually stopped restoring sessions since I got a little fearful about the security risks that could be involved with doing that.
None of my techs have experienced this problem on their computers.... but I really do handle a much larger chunk of the support requests. A 6/80 failure rate isn't very high either... so I don't know what to tell you! I just wanted to bring this to light in case it is a bug that could be fixed.