when I delete or reply to a pm, or vote in a poll, instead of taking me back to my pm box or to the poll thread I get redirected to the main jsp page? it's really annoying.

I havent experienced this issue. It doesn't redirect me to the main index.

What browser?

firefox

a lot of users had this problem before, not sure if they fixed it or if there is a fix (i think the post blocker add-on caused this problem)
make sure theres no add-ons causing this (disable them all then check if it still does this)
clear cache/cookies
try another browser

when did it start doing this?

Weird. Im also using firefox and have never had this problem.

I just deleted and cleared the trash folder and it kept me in the pm box page. odd.

Deleted cookies/cache/blahblah already I presume?

Checked both and it seems weird because it works fine for me.
Lemme think. Did You try to clear Your cookies/cache?
http://forums.d2jsp.org/topic.php?t=40774184&f=34

Maybe it is because of Retired Moderator group?

just cleared cookies etc, seems to be working alright now. Thanks.