FreeBSD 5.3 very slow data-transfer

[Jack Raats]

Yesterday I've install FreeBSD 5.3 on a machine. After compiling the kernel
with device my, I can connect through the network with that machine.
Everything works fine, but when I try to update the source tree or ftp-ing
to a local machine, the data transfer starts at 10 Kbytes/sec and drops very
quickly to nearly 0.
Can anyone give me a clue or help me?

Thanks
Jack Raats

PS. Before FreeBSD 5.3, the PC was working with FreeBSD 4.11 without any
problem.  I did a complete install of 5.3