When attempting to post replies in a thread, the page seems to process the request for several minutes before resulting in server timeout error. The post does end up getting published, though, when I check the thread page again afterwards. I get this behavior when posting quick replies as well as standard replies. I also get this behavior when attempting to preview my posts, which means I cannot actually preview anything because it times out, so I am forced to submit posts without previewing.
Additionally, this may be related to the use of quote tags inside my reply. I cannot remember exactly, but some of my posts which did not have quotes didn't seem to have this problem when I used quick reply.

I am using the latest version of Firefox on Windows 8.1.

EDIT1: Just confirmed it doesn't have anything to do withLS