I've got the same issue in Firefox 29 and 30 as well. I can reproduce it like this:
1. Open the admin page
2. Click an arbitrary page from the tree
3. Switch to the settings tab of the page
4. Switch back to the content tab
5. Watch it crash
(6. If it doesn't repeat step 3 and 4 until it does)
I've update my FF on Linux and now the crash report says:
- Signature: js::jit::IonCannon
What I find interesting is, that if I start FF in safe mode, then FF does not crash at all... However, if I disable my AddOns (NoScript, Firebug) or if I start FF with a new profile -- which should be the same as "safe mode", right -- FF keeps crashing again.
FF30 exactly the same for me
Switch to settings and then back to content a few times (take a few seconds after starting up to manifest)
and bang - every time !
Chrome is fine !
Come on Mozilla we need better than this!