SearchUsers limit?

System

I am trying to return a list of all users in a database and cannot get more than 512. I am using:

ObjAllUsers = objDB.SearchUsers("", imSearchAttributeType.imSearchID, True)

It is not a limit with my listbox and I have not been able to get more than 512 by modifying my client settings (max lookup or max documents). Is there anyway around this?
Thanks,
Ron

Migrateduser

Rookie mistake. I didn't set the max rows value for my session:

oSess.MaxRowsForSearch = 5000