I have already found out, that this is not ony problem of squid, but quite more general.
I wrote in a quick need of any help, but now i can see thic:
konqueror (direct) - after typing http://whathever.domain.xxx/
an error occurred while loading http://whathever.domain.xxx/
connection to host whathever.domain.xxx is broken
- when i refresh, no problem, page loads
this problem does not appear when i click a hypertext after this procedure
in the same situation, mozilla says "document contains no data" (refresh -> ok) and if using squid its as described in the first post
also, ping sometimes says "resource not available" and if you try after a while, no problem - without any changes made
i must mention, i added a new interface. but route looks fine and also shorewall is ok (the same problems while there's alowed everything)
you may say it's a hardware problem, but nope - the card is exactly the same as one of those used before, so no problem with recognising. and also it doesn't route to the net.
using mandrake 10 official, 2.6.3-13mdk, fully updated via auto updates