help. extremely slow upload to network but fast download

please help me.
i have 2 windows xp machines, the "server" is xp pro and the my laptop is xp
home edition, on 100 mbit router/hub.
downloading from the network share (server) is fast but uploading files to
the server is extremely slow.

a process which should take just a few minutes now takes over 250 minutes!

could this be a software problem? i did buy a LG's dvd-ram drive and some
softwares to use it.