This bugzilla is really two things - an RFE, which are not released in a z stream, and a legitimate bug fix.

The legitimate bug fix is that a user with gid of ais can't access the aisexec.  That bug is fixed.

The RFE is that a user with a secondary gid of AIS (ie editing /etc/group and adding that user to the ais group) is not resolved by this bugzilla.

We do not address RFEs in z stream releases.  I believe the RFE feature you want is addressed in 5.4 via the uidgid.d overlay directory feature which was added.

If you would also like gids in /etc/group file to be processed, you can open an RFE, but likely it wont be addressed until 5.5.

   1.
      [nstraz@try sts-root]$ qarsh -l testmonkey z2 id
   2.
      uid=500(testmonkey) gid=500(testmonkeys) groups=39(ais),500(testmonkeys)
   3.
      [nstraz@try sts-root]$ qarsh -l root  z2 usermod -g ais testmonkey
   4.
      [nstraz@try sts-root]$ qarsh -l testmonkey z2 id
   5.
      uid=500(testmonkey) gid=39(ais) groups=39(ais)
   6.
      [nstraz@try sts-root]$ qarsh -l testmonkey z2 /usr/bin/cpgx -i 5
   7.
      1244754000 D: do join our_nodeid 2
   8.
      1244754000 H: 00000000 conf 1 1 0 memb 2 join 2 left
   9.
      1244754000 H: 00000001 time 2 tv 1244754000.171467 config 0
  10.
      ...
  11.
      [nstraz@try sts-root]$ qarsh -l root  z2 usermod -g 500 testmonkey
  12.
      [nstraz@try sts-root]$ qarsh -l testmonkey z2 id
  13.
      uid=500(testmonkey) gid=500(testmonkeys) groups=39(ais),500(testmonkeys)
  14.
      [nstraz@try sts-root]$ qarsh -l testmonkey z2 /usr/bin/cpgx -i 5
  15.
      1244754053 ERROR: cpg_initialize error 29
  16.
      1244754053 ERROR: is corosync running?

Verified fixed with the above caveat, ais must be the user's initial login group, not a supplemental group.

An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHBA-2009-1103.html