Hi
There are two problems in fact, one is to import a customer object to a prod system during upgrade, and the second one is importing customer object from a system with a different version (your dev & qas should already be upgraded to Ehp7).
This can be an other reason for not importing that Y* report... as even if it is a customer program it can:
1) call SAP standard functions that are different between Ehp5 & 7
2) use tables / data elements that are changed by the Ehp import
Technically the import could be done (using unconditional mode "ignore invalid component version")
but there are no guarantee that the program will do what it is expected to do...
Regards
1090842 - Composite note: Transports across several releases
Transports of any application objects and especially Customizing transports between various release levels are generally not supported even if they work without apparent technical problems. If you are in any doubt, contact the SAP Support for the relevant application.