John,

Did you try to move the networkcard to another PCI slot ?
It did solve the problem for me.

Walter,

>Thanks all for the replies people. Here is what I have tried so far:
>
>(See original message for details.)
>
>Ran a new cable from the switch to the Dell.
>Ran Dell's utility to wipe the drive and set everything back to just out of the box settings.
>Installed NetBUEI.
>Removed the Modem card.
>Disabled virous chacking.
>
>Nothing changed. If no other computer has a file open then it's fine. If any other computer has files open then it takes 2-3 seconds to open each each shared file. The type of table buffering seems to make no difference.