Why is sending files much slower than getting over a windows network

[bazza]

Over a windows network , why is it much slower to 'copy to' another windows pc than to copy from?

details
PC A - Vista SP1, 640G Seagate, onboard marvell lan
PC B - WinXP SP2, 1.5Tb Seagate, onboard nvidia lan

A copies files from B for around 90MiB/s
B copies files from A for around 80MiB/s

A copies files TO B for around 20MiB/s
B copies files TO A for around 19MiB/s

any way to make sending files faster?

sorry if this has been asked before, if so just link that post thanks

 

[r_manic]

What's your router? Your problem probably has something to do with it.