Receiving a Communication Link Failure ODBC

Hi All,
I have a client using SQL Server 7.0 Sp3, and they have
clients connecting to it via ODBC (32) bit driver, some of
them are receiving a error message of communication Link
failure. They have MDAC 2.7.1 installed, they tried using
TCP/IP, and Name pipes, the error keeps happening.
If you have any ideas it would greatly be appreciated.
Thanks
ScottCan you ping the sql server when they receive the error?