Installed 4.2.1, then Last.fm now ATV won't boot all the way

I upgraded my 1st get ATV to 4.2.1 today, call me slow I know but I've been busy. Install went fine however Remote HD from my perspective is useless. XMBC/Boxee don't function because of an incorrect path and after I installed Last.fm the ATV boots to a black screen.

I reflashed my ATV to no avail, still boots to a black screen. I created a support ticket but am also posting here just in case you guys are faster than they are. I don't need my wife thinking I'm Tim Allen from Tool Time. :)

Same thing happened to me.  I hope you get a response/solution to the problem.

 

I got a response and tried what they recommended but it didn't work so I have restored the ATV to factory condition. I'm syncing now and will update the software after the sync has completed. After I'm done upgrading with the Apple updates I'll try 4.2.1 again.

Don't install last.fm.  I restored the AppleTV and I received the black screen after I installed last.fm again.  It looks like last.fm and Smart Installer are not working together.  Probably a last.fm update.

I've experienced the same problem.

How do you restore to factory defaults as I now cant see the ATV in iTunes either?

Press and hold the "-" and "menu" on the remote control

Oh no, I'm having the same problem.  wish I'd read this post first :-(

A quick fix has been posted here: http://forum.firecore.com/topic/3633?page=1#comment-12575

Sorry for the trouble.