Network transfer cuts out on large files

Here's a weird one for you - it's been confusing me for the past few evenings:

I currently have a network setup as follows:
Fileserver is Server 2003 running Virtual Server 2005 with Webserver1 as the Guest OS. I am sharing various files with Fileserver, which are accessible from all clients on the network. However, a problem has recently started occurring where large files (1GB+) cause the network connection to momentarily disconnect whilst copying it from Fileserver to a client PC.

Thinking it was a hardware issue, I've also assigned the on-board 10/100 network adapter an IP and have tried copying it from Fileserver to client that way, but the problem occurs. However, the confusing part is that not all scenarios result in a dropped network connection:

• Fileserver to Client - drops
• Fileserver to Webserver1 - OK
• Webserver1 to Client - OK
• 10/100 Fileserver to Client - Drops

I've disabled autodisconnect but that still doesn't have an affect on things. To test, I'm copying a DVD .iso Image of openSuse from Server to Client. As shown, I've also tried Host to Guest which didn't have a problem.

Anyone have any ideas of what else I can test? What could be the problem?

 

The exact error message is "Cannot copy [filename]: The specified network name is no longer available."

Microsoft's TechNet doesn't help too much, as I've proved the network connection itself isn't dropping, as I've been able to use remote desktop during a file transfer and don't experience any cut-out.

Anyone else experienced this? Trawling through many Google results at the moment to see if there's any clues.

EDIT: Also, both \\servername\share and \\192.168.x.x\L$ results in the same error.

 

(What did you draw the network diagram with? Looks linux-y)

Any reason why you have a 5 and 8 gigE switches? Maybe try it simplified and remove a switch and see what happens?

 

Visio for the diagram. I've left off a few devices to simplify things (XBOX 360, test rigs) and the 8-port is situated on the 2nd floor of the house, whilst the 5-port is located in the loft.

I will try a machine connected to the same switch as the Fileserver - but I don't think that's the problem, as I'm able to copy from Webserver1 to any of the clients and copy from Fileserver > Webserver1 without any issues. The problems arise when copying from Fileserver > Client(s).

Currently updating all drivers on the Fileserver, to see if that works.

 

It appears that updating the nForce drivers has solved the problem. Have just copied the 4GB .iso from Fileserver > Laptop via 54G wireless (took ages!) without any issues. The fact that the clients could copy from Webserver1 suggested it was a driver issue (as Webserver1 is Virtual Server).