File transfer on mapped drive: fast putting, slow getting.

I have a computer exclusively as a storage box with all of it's drives mapped to my main computer.

I just built this new box and I'm kind of boggled.

If i take a 200 mb file and move it from my main computer to my storage box, it will copy over in around 35 seconds. If i take that same 200 mb file and try to move it from the storage box to the main computer, it is taking 100 MINUTES. I don't understand what's going on.

Here's the specs:
Main computer: 2500+ athlon barton, 1 gb ram, onboard nvidia 10/100 NIC, seagate 200 gb sata drive.

Storage box: 2.26 p4 northwood, 1 gb ram, soyo onboard 10/100 NIC, maxtor HD's 160-250 (all ata133's).

These two computers are connected through a linksys 8 port router.

I have tried messing with the properties on the network adapter and forcing it to be 100 mbps but I haven't found a solution yet.

I don't understand why it could be fast going in, but so slow coming out. Something is limiting it in some way but I have no ideas as to what.

Any help would be appreciated. Thanks.