permissions 757 (drwxr-xrwx) unable to write?

[Rob Benton <rob.benton@conwaycorp.net>]

I ran into this at the office today.  There's a directory with this 
ownership and permissions

drwxr-xrwx oracle dba 4.0K log/

I'm part of the dba group yet I can't create a file inside that 
directory.  Only if I add write permissions for the group can I create a 
file inside that directory.

That seems really messed up to me.  By the way this is on a RHEL3 
machine if that makes any difference.