I actually talked to a Shaw Tech (he called me back about the specific issue) over a year ago about this limitation on the current 3400 program guide. My specific desire was to record NCIS on both CBS (current season) and Showcase (older seasons). He talked about how it could be done, but a year later, nothing has changed.
The current choices offered are to record a series on one channel or on ALL channels.
If you record a series on ALL channels you may get an SD recording and the HD recording that you really want will not be recorded since it is considered a duplicate.
I eventually purchased a second 3400 for sports, so I now record the current shows on one 3400 and the old episodes on the other 3400.So it's no longer a problem for me, but could be for other people.