JA Social is a template.
Jomsocial is a component and its latest version is 2.0.5 and it can be seen here: http://www.jomsocial.com/support/docs/item/765-change-log.html
Now, as I understand, current JomSocial 2.0.x is not compatible with Joomla! 1.6 and all future jomsocial 2.0.x patches will not support Joomla! 1.6 either.
I also understand that the Jomsocial team is working on making their software compatible with the latest Joomla! 1.6
I believe that if you are using the template JA Social on Joomla! 1.6, the component Jomsocial will not work. (If this is not correct, would someone please correct me).
The current version of Jomsocial is compatible with all Joomlart templates running on Joomla! 1.5.
The next release of JomSocial 2.2, scheduled on 1st March, will have full support for Joomla! 1.6 and you will be able to use it with JA Social. Looking at my clock, it should in less than 72 hours.