Lost Connections NW SBS 5.0

Running NW 5.0 (SP2) with various W95/W98 stations with mostly Client 3.20 and one MS Client. Users lose connection to server if they are idle >10 minutes while in a particular application (SBT Acctg). The msg is “CL32: File xxxxxxx could not be autoreconnected because file could not be recreated…”. Server console monitor shows no login for that connection but when the msgs are cleared at the station the login miraculously reappears. The server is up continuously. Its a 10-user net with one hub and only happens in that applic which is written in FoxproW 2.6. We have the same software running elsewhere with no problm. We also have another Foxpro app (Telemagic) that does not have this problem. What do I need to fix this?