ajax not working on buddypress frontpage

I am using the bp-default theme with few customizations(I have put in a jquery slideshow) apart from design changes. However, the ajax functionality of niether the slideshow nor the buddypress widgets for members and groups seems to work. When I click the group widget links (newest, active etc), instead of doing an ajax query it goes to the group list page instead.

firebug shows me the following errors:
j("div#members-directory-page ul#letter-list li a").livequery is not a function
$k("#slider").easySlider is not a function

To check whether it was a conflict between the slideshow code, I switched to the Buddypress social theme however, even that theme has the same problem with the livequery function.

I tried disabling the plugins that are active on the main blog but that didnt help either.

Can you recommend any other steps that I can take to get rid of the errors?

I am running WPMU 2.8.6 with BP 1.1.2. The site can be seen at http://bit.ly/Vjkd6

Thanks!