File Transfer speed

Hello,
We have 3 Intel servers running Windows 2000 Server (all identical), clients are using Win XP stations. The stations are suffering with file transfer speeds to and from these servers. When a station suffers slow transfers it will stay this way until you select network card properties(on station) and alter the connection (full or half duplex etc) the station transfer will then speed up til the next time it happens to the same station again then you just do the nw/card properties (doesnt matter what its set to or changed to). The same station which is suffering the speed problem can still transfer at normal speed to other stations and another Win 2000 Server (Proxy Server), other stations can still transfer to and from the servers at normal speed while others are slow. Transfer speed between the 3 servers is never affected, neither is transfers between the 3 servers and the Proxy. To eliminate any network infastructure problem we connected the servers plus some stations into the same 'out of the box' Switch and the problem still occured, we also swapped out the Gigabit cards from the 3 Servers back to the Intel onboard Nic's but the problem is still occuring.?
Anyone come accross this or have any suggestions before I become bald?
Any suggestions welcome to help.........

 

Take a look at

Q315237 (most likely)

and

Q321169 (possible)

and if you are running Kaspersky AV software

Q294756