Hi beerstein
Does /usr/bin/screenshot.sh look like this:
#!/bin/sh
[ -z ${DISPLAY} ] && echo "Requires X" && exit 1
filename=screenshot_`date "+%m%d%H%M%S"`.png
/bin/sh -c "sleep 1 && /usr/bin/imlib2_grab $filename"
If so, try changing the line that says filename= to:
filename=$HOME/screenshot_`date "+%m%d%H%M%S"`.png