Noticed a minor issue with class analysis and using custom RowCause (Apex Sharing Reason)
it reports an error that MyRowCause__c cannot be resolved.
I do NOT believe it blocks anything, noticed it under 2.0.?
Recreate: Create a custom object (Allow sharing) Set Sharing Settings for Object to be Private On the Custom Object add new 'Apex Sharing Reasons'
Sync down environment and try to access that via