ActiveRoles Server v6.7.0 ADSI Provder unable to add computers to AD group using C# .NET v3.5

The below C# code returns error: "Request to change a multi-valued attribute failed: attempted to add or remove too many attribute values. Not more than 1500 values can be added or removed from a multi-valued attribute within a single request." And fails at line 5.

1. static void AddComputerToGroupUsingARSProvider(string computerDn, string groupDn)

2. {

3.      DirectoryEntry de = new DirectoryEntry("EDMS://" + groupDn);

4.      de.Properties["member"].Add(computerDn);

5.      de.CommitChanges();

6.      de.Close();

7. }

However, if I don't use the ARS provider, and replace line 3 with "LDAP" as shown below it works.

DirectoryEntry de = new DirectoryEntry("LDAP://" + groupDn);

Any ideas?

Thank you,

Ray