problem with network performance, good speed only in one direction

[Vincent Immler <v.immler@12mm.de>]

Hi!
I've got a problem with my second pc which uses 3.5 (not updated yet), 
when I do uploads through WinSCP e.g. I can upload with 2mb/s (not fast 
indeed ...), but when I try to recieve files from that pc, I can only 
recieve with 10kbytes/s. Doesn't matter whether I try through WinSCP or 
an FTP-client. The problem is, I want to backup that data (~3gb).
I'm an OpenBSD beginner and I have no idea how to solve that problem, I 
hope someone else can help me ?
I already tried some hardware changes (different switches (always 
100mbps), cables etc) without success. Same problem when I try to 
recieve the files on another computer.

Best regards,
Vincent

P.S.:
bsdbox# netstat -i -n
Name    Mtu   Network     Address              Ipkts Ierrs    Opkts 
Oerrs Colls
lo0     33224 <Link>                               6     0        6     
0     0
lo0     33224 127/8       127.0.0.1                6     0        6     
0     0
lo0     33224 ::1/128     ::1                      6     0        6     
0     0
lo0     33224 fe80::%lo0/ fe80::1%lo0              6     0        6     
0     0
fxp0    1500  <Link>      00:e0:18:a8:65:90     1007     0     1101     
0     0
fxp0    1500  192.168.0/2 192.168.0.4           1007     0     1101     
0     0
fxp0    1500  fe80::%fxp0 fe80::2e0:18ff:fe     1007     0     1101     
0     0
xl0*    1500  <Link>      00:04:76:20:a2:8e        0     0        0     
0     0
pflog0* 33224 <Link>                               0     0        0     
0     0
pfsync0 2020  <Link>                               0     0        0     
0     0
enc0*   1536  <Link>                               0     0        0     
0     0

(sorry, just copied it from putty, don't know how to do that better)
as far as I can see 0 errors ?
also tried netstat -s, output to great to display in putty : \