It maybe still the "PROMPT_COMMAND" problem, do you have it defined? Since I use a special variable to guard the PROMPT_COMMAND, there is no slow startup problem.
Code:
if [ "$HH_PROMPT_COMMAND_SET" = "" ]; then
if [ "$PROMPT_COMMAND" == "" ]; then
export PROMPT_COMMAND="history -a; history -n" # mem/file sync
else
export PROMPT_COMMAND="history -a; history -n; ${PROMPT_COMMAND}" # mem/file sync
fi
export HH_PROMPT_COMMAND_SET="yes"
fi
