I often will ASCII Export and then ASCII Import a design back into PADS. The Bad Lines errors pop up but I never see anything missing; it seems this is something that you can't see from the GUI.
The error is probably from the line before the 'Bad Line' error is reported; something on that line confused the importer, so now it thinks the following info is a new command and reports the error.
I'd open the ASCII with an editor (I like Crimson Editor) and search for '-298 2733'; just make sure there aren't mulitple occurences. Then you can debug what data is causing the error.
Someone recently did their own study of what characters are acceptable. It was either on this list or the Yahoo! group. You'll need to search for it.