I, usually, wait to be informed by Seamonkey that there is an update, although I do not let it either be downloaded
or installed, but for the past two days even checking Help|Updates told me that 2.5 was up-to-date.
I, finally, downloaded 2.6.1 from the website ( I guess to match FF 9.0.1), and I got a surprise when it installed on top of 2.5, but it opened with a different profile. I have been using the -p switch to select the desired profile, and there is not much there, default, and a rudimentary Default User. 2.6.1 decided to open with the latter profile, but when I selected the default profile, everything was back to normal. I have, never, run into anything like this, in the past. So, beware, if you have more than one profile.
UserAgent: Mozilla/5.0 (Windows NT 5.1; rv:9.0) Gecko/20100101 Firefox/9.0