UNIX for Advanced & Expert Users

I have a user who has had an id change. His old id was xl00 his new id b000999. Both id's are in group bauser. The user now cannot access his old files even though he is in the same group and permissions seem to be ok. See below, first 2 files he can't see, second two are no problem.

Code:

-rw-rw-r--+ 1 xl00 bauser   39133184 Sep  3 12:44 motor_profit_31aug2012_grp.sas7bdat
-rw-rw-r--+ 1 xl00 bauser 1707155456 Sep  3 12:44 motor_profit_31aug2012.sas7bdat
-rw-rwxr--+ 1 7015 bauser    1040384 May 16 16:49 motor_profit_31dec2010_grp.sas7bdat
-rw-rwxr--+ 1 7015 bauser   61997056 May 16 16:49 motor_profit_31dec2010.sas7bdat

I can see all files and I'm in the same bauser group. CAn anyone suggest what the problem is. I thought about having execute permission for the group but I think that only applies to directories.

The + at the end of the permissions field indicates that an ACL (access control list) is present...

IF this is on a samba disk (PC->unix), you may see lots of ACL's on files, they can override, reduce or extend the base permissions.