Problems with modem connection to PowerPC

[papyrus@actcom.co.il (Avi Ashat)]

We have a PowerPC 7600/120 with a modem connected to it.
The modem is connected thru. the modem port and we use Smith Micro software 
(Mac Com Center).
Machine has 64M memory and the system is 7.5.3

During the install of the software it test the connection and the modem is 
lighting the Send and the Recive Lamp which means that there is a data 
commction path.

Still, From time to time the system losses the modem and we get messages 
saying that there is no modem attched or that the port is not recognised.

Can some one help us?

Avi Ashat 
E-Mail: papyrus@actcom.co.il