Noticed this last night and again this morning. It would appear the 'Quote' button (next to 'Reply' over each post frame in a thread) doesn't do anything.
I read recently that there had been some changes with servers and such on your end and I'm wondering if this is maybe a cache issue on my end? I'll dork with it a bit and see if I can't get it sorted on my side (and will post back if I do) but just thought I'd bring it up in case it was a larger issue.