Loading loop

This is a very serious problem. I think I’m running into a loop. So, here is what’s happening:
Whenever I try to access anything in the dashboard, the page seems to be loading, when it hits the sidebar, bam, ‘Problem loading page’, with ‘connection was reset’ message. I’m using Firefox 5.

This message began to appear, actually, gradually since I enabled my second site in the Network panel. And now, the entire backend panel (except the dashboard) is not accessible.
I found a post that indicate a problem could be with user and usermeta table. I checked the table, I found my entry (admin) with privilege level 10. I do just see one entry for my username, though, and even with two sites installed now, I only see one user table.
I also found a bunch of tables that have ‘2’ prefixed in front of them (I believe they are used for the second site), but there isn’t user table or user meta table prefixed with ‘2’. Could this be the problem? If so, how can I fix it?

Regards,
Angela