mac os x ff17 crashes

Erinn asked me to look into reproducing the OS X crashes.

Steps to repro:

Download TBB alpha:

https://people.torproject.org/~erinn/qa/alpha/ff17-osx/

Logging into twitter, then clicking on links from a twitter feed and making them open in new tabs all at once.

Any other things that I should test or report about my environment?