Just in, the release date of Thunderbird 184.108.40.206 has been shifted to Monday, March 15 as noted on the MozillaWiki Releases page:
I heard from BenoitRen from one of the Seamonkey forum threads at mozillazine, that he's unable to turn in a Win95 NSS patch now that Seamonkey 1.1.19 code freeze already took place, so that SM 1.1.19 can run on his Win95 computer. Too little, too late to submit it now. poor guy; I almost feel bad for him. He has to still run SM 1.1.17 because SM 1.1.18 and the upcoming 1.1.19 won't install nor work on his Win95 machine (unless he installs the IE shell32.dll v4.72.x update, which he hates to do).
I had random crashing problems with the 3/1/2010 SM 2.1a1pre nightlies yesterday. Seems like today's SM 2.1a1pre nightlies are more stable than the one I installed yesterday.