Systems Management

When we are going through the Helpdesk Ticket creation process, we have a strange problem occuring.  We select a define business unit primary category, and the sub categories are pulled from a different business unit.  REALLY odd   It's like it is not reading our defined categries correctly, only thing to do is start over and it seems to work correctly then.  Doesn't happen all the time, but it's pretty often.  Anybody run into this?