Damaged files on AppleShare 6.3

We are running AppleShare 6.3 on the servers at one of the sites I do tech repair for. The server is a 7250 and is running OS 8.1.
The question is….. Students are creating files on an older machine(580)and saving their work to the appleshare server. When returning to a newer machine to retrieve their work (iMac)the files have been damaged.
What is the cause of this. Could collisions in the network? Could the packets be damaged while in transit to the server?…..I tried to recreate the problem by creating a slideshow on appleworks using a 580. I saved to a folder on the server, and then opened it up on an imac and it worked. What do you suggest to try next?