Could not allocate space

Hello all,

First day on my new job and I'm hitting an error message that has been happening for the last few weeks and no one else has been able to come up with a solution.  I hope you can help.

SQL Server 2000 is throwing the error message:
System.Data.SqlClient.SqlException: Could not allocate space for object 'FileStorage' in database 'Mappingmaster' because the 'Primary' datagroup is full.

Here is what I have done:
I have increased the size of the datafile, from 2 gig to 3 gig.  Stopped and started the SQL service.  That allowed the client to perform its task (data synchronization) once.  All subsequent attempts failed.
I rebooted the server.  Client (different client) performed synchronization once, all subsequent attempts failed.
I added another datafile to 'Primary' datagroup.  Stopped and started the service.  One success, all subsequent attempts failed.
Stopped and started the service again.  No difference - no success.

Between the two data files there is over 5 gigs of space and only 3 gigs have been used in the last eight months so I don't think it's a problem with the db not 'growing' fast enough.  There is still over 110 gigs available on the drive.  There is a total of 19+gigs cumulative in databases on the server so I don't believe it's a licensing issue (but it anyone knows how to confirm that I'd appreciate it).  I've checked the log size and it is only about 1 meg of the 7 allocated (after a backup) and it is set to autogrow along with the datafiles.

Event Viewer on the server shows no errors during these attempts but the client displays the errors referenced above.  The server does show:
Event Type:      Information
Event Source:      MappingReplication
Event Category:      None
Event ID:      0
Date:            6/30/2008
Time:            10:48:44 AM
User:            N/A
Computer:      TRC_DELL2800N
Description:
Exception in ReplicationConn process:
 MsgCode= AK
MappingLogic.MappingException: Timeout exceeded on network receive
   at MappingLogic.ReplicationMsg.SafeRec(Socket sock, Byte[] aBuff, Int32 SizeToFetch)
   at ReplicationService.ReplicationConn.Process()

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.
If that is unrelated, don't worry about it.  I'll come back to that one at a later time.

Now that I've typed all that out, I'm thinking the problem may be with the clients and that - perhaps - they have the MSDE with a two gig limit as part of the client app.  Still, if anyone has other ideas please share them.

Thanks,
bvinson