Thanks Faterson. You say:
1) install the new universal Marvin version on your iPad. You will now have 2 Marvins on your iPad.
Thatīs just what I canīt do. Itīs showing the new version as Downloaded and wonīt let me download again. But I havenīt downloaded the new iPad version.
Any suggestons? If not, I guess Iīll have to delete the existing version, losing my library, redownload and try to find all my downloaded books again.

Thatīs a royal pain.