I created a site http://run-x.de/J25/ and Firefox hangs when I go to "Collection" or try to zoom in ... Reinstalling the browser did not help.
Defaul Browser of Android 4.2.1 works very well ....
I can not reproduce your crash by clicking on the collections section of the site. What phone do you use? Do you have crash IDs? Uninstalling Firefox will remove old crash reports, so you will have to play the crash at least once to recover a crash ID.