Description of problem:
The error message states the a non-existent group already exists is you try and add a new group with a gid already in use.

Groups in DB:
[root@jennyF11 etc]# ldbsearch -H /var/lib/sss/db/sssd.ldb -b "cn=groups,cn=LOCAL,cn=sysdb"
asq: Unable to register control with rootdse!
# record 1
dn: cn=Groups,cn=LOCAL,cn=sysdb
cn: groups
description: Local POSIX groups
distinguishedName: cn=Groups,cn=LOCAL,cn=sysdb

# record 2
dn: name=group1009,cn=groups,cn=LOCAL,cn=sysdb
objectClass: group
name: group1009
gidNumber: 1009
createTimestamp: 1248293073
member: name=user1009,cn=users,cn=LOCAL,cn=sysdb
distinguishedName: name=group1009,cn=groups,cn=LOCAL,cn=sysdb

# record 3
dn: name=jgalipea,cn=groups,cn=LOCAL,cn=sysdb
objectClass: group
name: jgalipea
gidNumber: 500
createTimestamp: 1248204348
distinguishedName: name=jgalipea,cn=groups,cn=LOCAL,cn=sysdb

# returned 3 records
# 3 entries
# 0 referrals

Error Message:
[root@jennyF11 etc]# sss_groupadd -g 1009 group1008
The group group1008 already exists

Version-Release number of selected component (if applicable):

sssd-debuginfo-0.4.1-1.fc11.i586
sssd-0.4.1-1.fc11.i586

How reproducible:
always

Steps to Reproduce:
1. add a new group and assign a valid gidNumber
2. try to add another group with different name but same gidNumber
3.
  
Actual results:
The group group1008 already exists

Expected results:
Error message stating that the GroupID is already in use

Additional info: