Glad I read the whole thread through... was just about to file a bug report for "unable to enter comma in country codes to exclude" but found it's already been reported.

There's a couple of North American metropolitan areas where this is an issue because they're run out of numbers and created overlays. For example I have a +1604 number but can also dial +1778 as local (eg my wife's cellphone is 778) so I need to exclude "+1604,+1778"

[Annoyingly there are some 604 and 778 numbers which ARE long distance, but they're the minority]

You've probably found the issue already but, in case you haven't, it's cos you specify the ImhDigitsOnly InputMethodHint for the lineEditCountryCodesToExclude field

Great app by the way - one of the core missing features on the N900 as far as I was concerned.