I tried 3.09b on RB133c and it's very bad.
I think that RB133c is suitable only as client and in this time we need only "station-pseudo bridge" mode on it.
Why you don't make separate "lite" version for RB133c?
Download page is prepared for it.
Then make real full-package for RB133c with only basic packages as wireless, system, security, routerboard.
And make it for RB with less memory.