Hey Scott,
that's all the ideas I got.
Other things that could be worth looking into...
-a different software security program could be blocking; i've seen it happens with other users who didn't realize they had more than 1 installed/running.
-if you're on a protected network - this kinda thing happens on a company network where they restrict certain employee internet privileges. Highly unlikely on a home network but you never know if it could be set.
-using an outside/public wi-fi connection. The connection is so low/bad it can't do certain internet actions as well on a home network connection.
-review you network settings just to make sure its not set too high where it blocks out certain internet actions
-if you're on wifi, see if you can test the problem with a standard wired connection.