Hi,
I have the same problem, but it's not an issue of firewall, I don't think.
I can download the webpage using wget, and even when I open the the cartridge I can browse the thread (via "search BBS thread") but when I press "x", pico returns an error "could not connect to bbs". Do you have an idea how to debug this?
I am posting here becasue I am also on linux.
Loving pico btw :)