Radio button & Option list values migrate successfully with Feeds Importer but disappear in node edit
I don't have enough reputation to comment, so I'm posting this as an answer.

I'd suggest that you install and enable the devel module to compare the data structure of the field in question in these three situations:


when the data is input manually
when the data is loaded via feeds
when the data loaded via feeds is later edited


If you haven't used it, with Devel installed, you can get the 'devel' view of the node.