BACKGROUND
Using Xdebug with PHP and Komodo IDE, and Eclipse PDT.
Xdebug is installed on the server and working properly. This is confirmed
This is something I would definitely want to include in the Xdebug documentation. I think it would work best to have many people collaborate on this, so I've created a file in the xdebug.org github repository (https://github.com/derickr/xdebug.org/blob/master/html/docs/tutorials/troubleshooting.rest) to collect tips. Feel free to fork and extend!
On the Xdebug side, in the upcoming version (2.2) it already dumps in its xdebug.remote_log file a couple of extra diagnostics such as whether it tried to connect and whether the connection was accepted or denied.