I just clicked it, and it still takes me to www.register.com. So, I am not sure what you mean by - "It's back to normal." Has the site been hacked, or what?
Domain registrations - domains in general - sort of "percolate" through the nodes on the internet, and not all update at the same time, so - depending on the hop your connection is taking - one time you may go through a server that does not have the updated info, and another time, you will go through one that does. It was definitely an expiration issue: here's a snippet of data from their registration:
Comments
Ray
This is what people saw:
http://www.avrfreaks.net/modules/PNphpBB2/files/mchp_294.jpg
-Phil
-Phil
Domain Name: MICROCHIP.COM
Registrar: REGISTER.COM, INC.
Whois Server: whois.register.com
Referral URL: http://www.register.com
Updated Date: 25-may-2011
Creation Date: 24-may-1994
Expiration Date: 23-may-2013
Some registrars give a longer grace period than others, looks like this one went right offline when it expired.
I admin a little over 100 domain names... it gets to be a full time job to keep on top of renewals with that, hosting, redirects...!
Dave