What a shame.
It sounds like the authorisation didn't work, despite that it said that it did. Similar to the thread I linked to: maybe your number of maximum devices to authorise has been reached. This doesn't necessarily mean you have more than 6 devices authorised, but that you authorised maybe one or two devices more than 6 times (Adobe has a stupid system).
To be sure this is the problem, you could test this by de-authorising your Sony, and then seeing if the Touch will be allowed to view the books. But you could also skip this step and go straight to trying to solve it:
The only way to solve this is to
contact Adobe and have them reset all your authorisations. You'll have to re-authorise all your devices after that (so your computer and eReaders).
Edit: something like
this might also be happening?