2.4.19 Networking Wierdness

>      Briefly, with 2.4.19 I can't get to certain web locations while other 
> locations work just fine. I see the problems with plain ftp, mozilla and with 
> lynx.
>      Not so briefly:
>      I upgraded my kernel (compiled from source, etc.) to 2.4.19 about two 
> weeks ago. Everything seemed to be working but yesterday I noticed I could 
> not access some web and ftp locations. After suffering the "You're not 
> running Windows?" discussion with Qwest technical support, I was embarassed 
> to notice that other systems here worked fine. The problem was limited to the 
> one machine. I sheepishly told the Qwest technician "never mind" and started 
> trying to debug the situation.
>      A few minutes ago I rebooted that machine with the previous kernel, 
> 2.4.9_34, and found those same locations now working. In 2.4.9_34 it works, 
> in 2.4.19 it fails, but only for selected web locations. For what it may be 
> worth, the failing/working web locations are www.users.qwest.net and 
> ftp.users.qwest.net.
>      Anyone recognize what's wrong or know where I should go to research this?
>      Any/all tips/suggestions would be most welcome. I'm looking for 1) a 
> fix, and 2) a methodology to resolve this on my own next time. (I'd 
> appreciate both a fish, and being taught how to fish.)
>      TIA