First of all, what version are you using? And what editing mode are you in (Normal or Advanced)?
I just tried to do this report and it worked just fine. I chose source type, Source Number, Abb1 and Footnote 1. I know that if there isn't anything in the abbreviation field that there can be problems, but I'm not sure if this was just a problem in the early versions or not.
Did you print out a Source Summary Report, or just try to make up this report list first? To print a summary for all sources, use the Source Search feature to create a list of sources. Is this what you are trying to do? You might also try (before you attempt your list again) to do a Project/Utilities/Check and use the rebuild/streamline option.