Subscriptions on Multiple iPads

I can't get a straight answer to this.

My wife and I both have iPads, and we share an iTunes account on both, so that we can share the apps we buy and for ease of data transfer.

I bought a one-year subscription to "The Daily" - which worked fine for a few days after I paid for it. Then, I went to the other iPad, downloaded the app (with the same iTunes account as the first one), launched it, and it asked for my iTunes password. I entered it, and it proceeded to load the current issue.

However. The next day, when I launch the app, I get a message that it "cannot connect to the iTunes Store" - but when I dismiss that dialog, it loads the current issue. On the other iPad (the one I originally paid for the subscription on), I now get the dialog box with the standard offer to pay for the subscription, and no current issues are being downloaded.

There is no indication in the App Store that a subscription is good on only one device. Even if it were, can I pay for two subscriptions from the same iTunes account, or will that cause some kind of logic fault that might invalidate both subscriptions?

If anyone knows where I can find the answer to this, or even to pose the question, I'd be very appreciative.

Thanks!

John S.
Baltimore, MD