Can't get serial SMC1 and SMC2 working together

Hi.
I'm using a TQM823L board, ELDK and Linux 2.4.25 (from denx). My
problem is that i can't use both SMC1 and SMC2 at the same time when I
disable the console
(console=3Dnull).

I use pppd and a gprs on ttyS1 and this is working fine (I use another
computer pinging the modem). However, the instant i open ttyS0 ("echo
test > /dev/ttyS0"),
ttyS1 is affected and the modem goes down (ping timeout).
The behaviour is consistent over other scenarios as well: I can access
both ttyS0 and ttyS1, but not simultaneously.
This is strange since ttyS0 and S1 seems to work together nice when I use
ttyS0 for console.

Can anyone help me solve this problem? I get the feeling i'm missing someth=
ing
trivial here.

Regards,
Doug