The only thing vaguely similar that I've run into is one or two sites that download so much adware that the keyboard - and mouse - are blocked for a time during page loading, due to the heavy "send" traffic.
I also occasionally get a temporary "locked" condition when I accidentally click to some video and/or slideshow pages, apparently because the site force-feeds their presentation.
So far as I can tell, everything resembling your description is specific to the sites, and has nothing to do with your own setup. The effects are emphasized by my slow dial-up connection, so others with quicker bits might not notice them (as much).