Okay...well, try to find out what group has access to the device, and add the non-privved user to that group...
Enter this as Root, in the console:
then do the same for the user, add the user to the group that is allowed to the device
As for the exit codes, these are listed, try this one for appetisers:
grep 64 /usr/include/sysexits.h
...and then, replace the 64 with 1 or 2...