I can't get access to a folder on our server and can't understand why. Perhaps someone will see what I'm overlooking...

Trouble accessing /Library/Subdirectory/NextDirectory/

User joe can ssh to the server just fine and cd to /Library/Subdirectory/ however trying to cd into the next folder, NextDirectory, gives this error:

-bash: cd: NextDirectory/: Permission denied

both username joe & bill are members of the group admin and both can get INTO Subdirectory without any trouble...

hostname:Library joe$ ls -l | grep Subdirectory
drwxrwxr-x  3 bill   admin   102 Jun  1 14:51 Subdirectory

and from w/in the Subversion folder

hostname:Subdirectory joe$ ls -l
drwxrwx---  5 root   admin   170 Jun  1 22:19 NextDirectory

bill can cd into NextDirectory but joe cannot!?! What am I overlooking? What tools do we have to troubleshoot this?

thanks!