There's an easy workaround for this problem. It only happens when the main contact you start up with has a blank note. To work around this problem:
1. Type something into the notes on the main contact you see when you start TntMPD.
It could be as simple as typing in a space or a single character.
2. Then save your change (File|Save).
(This issue will be fixed in TntMPD 2.1 r36 when it comes out.)