Nah, you're not the only person who fell for the single post design.

Yes, you could say it's draping the bag. Let's start with nomenclature first so we are on the same page. We are talking about an ordinary rollerbag like this
http://www.luggageonline.com/product...roduct_ID=6347

What you can do with such a bag is this
http://img.systemaxdev.com/productme.../136149-sm.jpg

But you cannot do that with the single post bag.

So you take the strap, that is often delivered with the roller bag, you attach on side of that strap the the roller bag's top handle (to the fixed handle, not the collapsible one). The other side of the strap (usually a pretty short 5-10" strap) gets attached to your additional bag's handle. The additional bag is now hanging in front of the roller bag's front panel. It stays in place by friction and by the fact that the strap is too short to allow any swinging to the side.

I didn't find a photo of that but it should be clear and you might have already seen this at airports. If the single post roller you bought does not even have such a strap, then I really feel for you.

You can buy a strap at Briggs and Riley or probably Magellan or you can make one yourself.

Till