Spinner not displaying properly in Ajax subscribing

I can confirm the spinner doesn't show up. This works in my local dev environment, and it's just a background property on the class for the "Subscribing..." element. So I'll need to track down what's going wrong in production that it doesn't show up.

As for the odd behavior you describe and have screenshots for, I couldn't reproduce this exactly. The subscribing behavior worked fine for me and behaved as expected (save for the missing background spinner). However, when investigating the missing spinner image in Firebug, I did see something sort of like what your describe -- with Firebug open, clicking the link would add the subscriber name but not change the 'Subscribe' text, but for me, a full page reload cleared this. Can you help me find a reproducible case for this or confirm it was some glitch related to Firebug (or something similar) for you as well?

I've also filed bug 374805 about an issue with Opera (the unsubscribe icon isn't in the right place after subscribing, but is fine after a reload). Can you take a look at it to see if there's something easy we can do to fix it?

Since the issues with subscribing not working and adding a name to the subscribers list twice could not be confirmed, I updated this bug to better reflect the remaining issue -- that the spinner is not displaying beside the Subscribing... or Unsubscribing... text.

Fixed in devel r8429.