This morning I was able to fix error 1001 with my Silverlight player in Netflix. I went to tools, internet options, security and finally trusted sites. I added both of the following entries: https://*.netflix.com and http://*.netflix.com. Of course, I unchecked require server verification for the latter to be accepted.
Just for good measure, I went to the general tab, hit delete and then delete all, including files and settings stored by add-ons. Voilà! The player works as it should. I would like to take this opportunity not to thank Netflix for this fix as they apparently don’t know about it or are too lame to post it on the page that you are redirected to when you receive error 1001. I hope this helps someone as it was most irritating to me.