Carl, I never had any crashes until I completely uninstalled it and reinstalled it because I was having problems getting Flash to work. I still don't think the problem is/was Firefox as much as Adobe Flash 10.`
Welcome to the forums Shim.
You can use a gallery script or you can go to Hotscripts.com and look for a suitable script. If you are going to go with a script please be sure the you secure the script so that it only uploads image files.