I sometimes make modifications to a language file in one of my bundles. I make the changes in TextMate 1, check them into a git repo, then I pull the changes into my Avian bundles directory. Sometimes, but not always, if I do this while TM2 is running it causes TM2 to crash.
On a positive note, the times that it does not crash, TM2 detects the changes and open files reflect the change immediately.
I guess since you guys get the reports, you may already be aware of this, but I wanted to report it since it has happened more than once.