Comment 2 for bug 1727470

I didn't have time to look into the source code, but the problem is that instead of having something like "Cdrom with %s", there is a new translatable string with hardcoded version added every time a python-apt is released for a new Ubuntu version. You could probably make the "Ubuntu xx.yy 'Code Name'" string not translatable (I don't think anyone actually translates this) and use it as a part of the "Cdrom with ..." string.