Knoppix is losing connection on T1 and cannot resolve DNS

Hey
i installed Knoppix on hard disk and it works OK. But very offen my Knoppix is losing connection to internet. I have fast lan connection to internet ( 1 Mbit ). There is very offen message that my WWW browser (Mozilla or Dillo) cannot resolve DNS. Even , eg. when i use apt-spy it is going and after while there is the same massage.
I checked my configuration on Debian Woody and Windows NT 4.0 and it is OK. I have three dns`s addresses and all are OK and works.

My KNoppix is 3.1 ( date : 20.01.2003 y. ) , it is upgraded using apt-get upgrade.

regards
adam0ski