Network fails on Lenny

["Alejandro Barocio A." <abarocio80@gmail.com>]

When I installed Lenny with the official DVD Binary 1 the network
connection stoped working. Previously, I had Etch 4.0_r5 And
everything worked fine.

My greater concern is that I still can recive my email via POP
and use messaging with XMPP, also I can connect to my computer
via SMB, HTTP (and, I *fear*, other protocols; so I can be accessed
by the world, but can't access the rest of the world). No output
protocols wok!

I use to think that the problem was on a WinXP I use as gateway,
but my machine didn't work on ant other connection (not even direct
connection to the DSL modem nor 3.5G USB modem).

Can anybody tell me what's the problem?, or where can I start?

-- 
Para vencer, hay que ceder;
Para aprender, hay que desconocer;
Para ser libre, hay que servir.
     A. Barocio A.