Strange network behaviour

[Vincent Zee]

I am really at a loss at the moment.

I have a 100baseT network at home and all connected machines have 100Mb 
network cards.
When I upload mp3 files from my ibook to the FreeBSD server the speed 
drops to 100kb/s.

This only happens between these two particular machines. These same 
machines connected to other machines give the expected transmission 
speeds. I checked cables, switches and router but found nothing 
unexpected.

Any hints, ideas or even solutions are most welcome.

The FreeBSD machine is running 4.7 and the ibook 10.2.4

/\
Vincent