Outliner / ToDo List

I have been looking through this forum for a Outliner / ToDo List, and have found a number of good suggestions. The one thing I have not found is one that I can import my old lists into. I have extensive lists under ShadowPlan (Palm), which now appears to be abandoned. I would like to import these lists.

I tried Outliner and I was able to import 1 list, but no more - I keep getting the error of "read error or not an import file".

I have looked at NoteLynx, which seems very good, but cannot import. Before I spend anymore time trying apps, I hoped someone might suggest a good one.