Unable to add LDAP group into a local group when using Delegated Authentication Directory

Steps to Reproduce

1. Create UserA in LDAP
2. Create 1 group in LDAP called ldapgroup
3. Assign UserA into ldapgroup
4. Set up a Delegated Authentication Directory in Crowd, with the Use Nested Groups and Sync Group Memberships options checked
5. Login to Crowd as UserA, so that the LDAP membership details are copied to Crowd
6. Create a new local group in this delegated directory called localgroup
7. Click "Direct Members" tab for localgroup and add ldapgroup into this group
8. Login to Crowd again as UserA

Expected Results

ldapgroup is still a member of localgroup

Actual Results

ldapgroup is removed from localgroup and there is an error in the log:

2013-09-06 16:28:11,420 http-8265-6 INFO [atlassian.crowd.directory.DelegatedAuthenticationDirectory] Removed group "ldapgroup"'s membership of remote group "localgroup" in directory "Delegated Authentication Directory".