Percent character breaks Terminal
Looking at your .bash_profile, this seems to be the most suspicious line:

trap 'printf "${OPENTITLEBAR} `history 1 | cut -b8-` - `pwd` ${CLOSETITLEBAR}"' DEBUG


It is doing a printf on the history (which will contain your % character). 

I have no idea what that is intended to do (update window title with last command?), but I would guess if you comment it out, the error will stop.