SQL 6.5

When out clients connect to the SQL database housed on a seperate server the connection timesout to only one of the tables. The clients as well as the server is running WINNT 4 sp 6a. THis is anintermittent problem (Works for 15minutes – down for 10) that tye of thing.
The clients are definately connecting to the server as authentication occurs to the same database,just a seperate table.
Any advise would be greatly appreciated