Roaming Profiles & Metaframe 1.8

We are experiencing a problem with roaming Roaming Profiles (from the metaframe 1.8)not loading on the users systems. It does not happen all the time and the systems we use are 95/98/2000. We get error messages that user desktop can not be loaded or cannot locate profile contact your system administrator. There are a couple more messages but can not remember them at this time. Any help be wonderful.
Robin