Purchase Order - Copy Document

We use blanket PO's heavily and use the Copy Document function to create the 2015 blankets from the 2014 ones.  We noticed this year that the new blankets appear to be a copy of the "original" version of the one it was copied from and not the latest revision as we had expected.  Last year we made many changes to several of the blankets, including updating unit prices and cancelling many of the lines.  And now we have to make those changes again in the 2015 blankets because they weren't copied over.

Can anyone confirm whether this is the intended functionality of the Copy Document function?  The user guide is a bit vague about whether it copies the original version.