When I was installing Debian Squeeze on this PC, I was asked about some non-
free firmware for my NIC (rtl8168d-2.fw). I didn't have it. But anyway, I was
able to install the system (downloading files from the mirror), surf the
internet after the installation (Iceweasel, Epiphany) and even download
updates. The problem is that the network icon always showed the information
"connection not present" (something like that). The "real" problems started
when I was trying to use Evolution and configure my e-mail. I realized that it
could not connect because it said "no connection". I think it's the lack of
firmware that is affecting these other programs.

retitle 601340 default n-m config prevents evolution from working
thanks

Hi,

Thanks for your report.

Then this has nothing to do with the NIC firmware. Indeed, as you said and as
mentionned in #601340, the firmware is actually not needed.

Not sure how/if d-i can stop asking for the firmware.

This is #549451 (evolution cannot work when network-manager is in offline mode) combined
with default network-manager as of today #530024.

As a workaround, edit /etc/network/interfaces and comment references to eth0.