I have the same thing. Tested this in the quick install set up as well as my clean install package using the updated Joomla, Gavick Template and Jomsocials latest release. The main menu works perfectly but as soon as i log in to jomsocial the main menu is just white with no links. Cant check the main menu module settings as its not set in module manager but in the template config.
PS. are we back to using the forum for questions again or should i be using the support desk?