Tom Young is right -- this is just a case where the "guide me" interview isn't sophisticated enough. I'm basically following the last part of his answer. In the end, I found that I could enter the form view for the imported 1099-B worksheet and adjust one of my transactions so that it contained only the info from the ESPP sale lots. I then added another transaction for the RSU sale lots, so that all are accounted for. Completing the Cap gain worksheet and employee stock worksheet for each transaction produces the correct cost-basis.
