version 1.5.0.9 (20070104) is what I use. I do build it from source but that shouldn't make any difference.
i've never successfully managed a build of anything-mozilla. not that it's a priority ...
I try to avoid pre-releases for things such as T-Bird/Firefox and am not sure you could actually revert back to the 1.5.0.9 stable version.
FF2 & Tbird2 have been, generally, far more stable for me than their 15x counterparts ... but, yes, "it's a beta".
Looks like there are some options gone missing in the 2.x branch. ::sigh::
alas, yes.
