[otrs] Package Manager Error

I've just installed otrs and everything is working fine EXCEPT that I get the following error when I click on the link for the Package Manager: Software error: ERROR: Need write permission in OTRS home Try: $OTRS_HOME/bin/SetPermissions.sh !!! I've run SetPermissions.sh and it doesn't help. I successfully ran Package Manager once (though I didn't actually install any packages). Now all I get is the error. In the system log, I see the following line: OTRS-CGI-10 Can't write file /opt/otrs///check_permissons.20334: Permission denied! Any suggestions as to what file/folder is having the problem? Thanks.