I installed this excellent workflow in a second account on my Mac today and had problems getting it working. The pbauth command wasn't working. After looking at the debug console for the workflow I noticed that the workflow was trying to write to the file '/private/var/tmp/alfred.pinboard.log' and was getting "Permission Denied". After changing permissions on that file to rw-rw-rw- (666) I was able to get pbauth to work from the second user account. You may want to create that file with these permissions, if possible, to avoid this problem.