Total newbie at bitcoin; long time Linux user.
kubuntu precise 64: My first attempt was just to download it (a slightly older version than the one from the ppa below), untar it and run the executable. That worked fine and it was downloading the data (block chain?). Then I played with some settings and it stopped downloading. I tried a bunch of things with no success.
Among other things, I tried encrypting my wallet and changing the network settings in bitcoin about the time things stopped working.
Then, I deleted the whole tarball, the expanded files, and the .bitcoin directory tree and installed from apt using the instructions at: Installing Bitcoin-Qt on Ubuntu
It still won't download anything. It says "No block source available ..." and debug.log ends with a ton of messages which say 2014-04-19 13:36:21 connect() to 192.168.1.2:8333 failed after select(): Connection refused.
I went into my Actiontec gateway and saw that a port forwarding rule had been created by uPnP for 192.168.1.2:8333 (that's my notebook address with the port added) that says TCP any -> 8333. I have other rules using this IP - without the port on the address - which forward ports 587, 995, 5192.
When I go to http://www.canyouseeme.org/ , it tells me port 5192 is open (I have another application using that port), but it says "connection refused" for 587, 995, and 8333.
Any clues as to what I'm doing wrong (or what I should be doing instead) would be appreciated.
I can't figure out why the original attempt was working and then stopped.