Having problems with rc.local

[jim ruxton]

Hi I'm having a problem with a script I put in rc.local and I was
wondering if anyone has any suggestions:
Below is my script:

touch /var/lock/subsys/local
/sbin/rmmod uhci-hcd
/sbin/modprobe uhci-hcd
su - jim -c /home/jim/capture/camera_start_script.sh &

 
What I want to do is unload and reload uhci-hcd and start another
script. I have a camera attached to a usb port and when the pc boots it
doesn't load the camera driver correctly but if after booting I reload
the uhci-hcd script all works fine. If I manually run rc.local this
script works fine as well. So I thought rc.local was the last thing to
to run but for some reason running it manually and letting the computer
do it during bootup gives different results any idea why?? I know this
is probably confusing. Thanks.
Jim