I was helping a friend setup CQRLOG and FLDIGI on Ubuntu the other day. It is a pretty simple setup except for one little oddity, that is critical for many of us: rig contol
In order to get the USB-->Serial adapter to work:
sudo adduser MYUSERNAME dialout
I had not run into that as an issue with previous setups (likely with older version of Ubuntu). I am not sure if the permissions changed between the version of Ubuntu or maybe some other software installation took care it automatically in the past.
73 de NG0R