Just out of curiosity. What browser are you using? The reason I ask, (and this may be totally unrelated), is that for some reason lately FireFox has been doing this to me.
This is on Update pages that have been fine for months. If I open the same page in Safari or Chrome and do an Update, it's instant. Back to FF and it just spins forever. Most of the time I have to quite FF completely and then reopen the page.
The Update is usually completed using FF but it keeps spinning and we wait.
I'm experiencing this using FF 12.0 but 11.x was also doing it.