I'm having the same problem, Walt_Moose. I installed Avast 5.0.396 a few days ago and at that time the registration button in the user console worked fine....registered it in just a few seconds. BUT, noticed last night that Avast had not automatically updated the signatures since that initial install. *bummer*
So I thought today "I'll just reinstall and see if that's the problem". Well, long story short, upon reinstalling the registration wouldn't work AT ALL. I figured out the auto update problem was the tick box that says "I connect through dial up modem". If I keep that UNchecked it will update fine. However, I still can't register. Tried the normal online way, and after pressing the button, the internet activity lights (the monitors in the taskbar) briefly show something being sent, but that's it. No other action and no registration. So I tried the manual key generator right below the normal one in the console. Got the key, copy/pasted it, and was told it was not a valid key. Just now tried the manual link posted by Rednose above, and it's been a half hour now with no email key sent yet. I know the page says up to 24 hours, but it's never taken over 5 minutes in the past.
Don't know where to go from here really. If they won't register me, I can't use the program. *sigh* I'm beginning to wonder if their registration server is down or something.