Inconsistent behavior when dragging and dropping work items

After some reading on jazz.net, I get the impression that the following works as implemented. However, I find it inconsistent:

I have stories and tasks in a team backlog. Some stories have tasks because they got them in an iteration but then could not be finished and were moved back to the backlog.

When I now have the sprint backlog and the team backlog side by side, move the story in question to the sprint backlog, I get the question if I also want to move the tasks. This is really helpful!

But If I just view the team backlog in Iterations view mode and move the story to an iteration, I get no question and just the story is moved without its children. To avoid this, I need to expand the story and select itself plus all children, then drag it to the iteration.

I know that I had the same behavior in RTC 1.0, too, but today I struggled again with this.

Is there any reason why this is implemented that way?