OK then, I looked in the CC network settings and I had no dns settings; just empty fields and selected was: 'get dns servers from DHCP'.
No dns servers were filled in in my modem/router either. But when I fill them in it doesn't make a difference (in config page of modem and CC - I did not yet try the text file). However, when filling in settings in CC, I didn't fill in Gateway, because I can't find the settings for it.
I did find out that when I use a specific gamescanner (from bdamage.se) I could connect fast, as it should, so as long as I use that program, the connecting to server is solved except from within the quake client (weird enough).
And ifcfg-eth0 has everything filled in, incl. dns nr's. I tried the google nr's too, didn't make difference for quake client or mail. I did try out a different quake client which can connect fast... so now I'm really confused
BTW: I forgot to add that the mail client doesn't make a difference (claws, thunderbird...etc) and the provider uses no encryption whatsoever (yes, very unsafe).
To be honest, even though the mail stuff is slower then in winxp, I can live with that. I just wonder why.