The iOSRA driver will only work with one installed version of Marvin. The scanning order is:
1) Marvin universal
2) Marvin universal free
3) Marvin for iPad
You can use
iFunbox to connect to your iDevice and copy the contents of your Documents folder and Library/mainDb.sqlite from your old installation, then add those to the new installation. Make sure that you have force-quit Marvin before doing this. I believe that Kris has a blog tutorial about using iFunbox somewhere.
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