This has happened to me as well. Usually what happens is that the sponsor does it over the phone, and then doesn't go to the airport to sign the authorization. For example, recently .bomb was having difficulties in allowing on-line sponsoring with CR1s. So they were called in.

When this happens, one needs to call the 1K desk and asked to get transferred to the 1K web support. Be prepared to sit on hold for a while as they take care of it. But it has worked so far for me.

And if you sponsor an upgrade, if it wasn't done from your account on-line, you'll need to make sure you authorize it correctly. I did this at the RCC in SFO for +1.