That message indicates there was a formatting problem with the data sent from the server running your blog to your browser. This all makes me think that one of those plugins is doing something to change that output.
I've seen that with some plugins that try to change time formatting or try to add a script or style sheet to every response. I would suggest you contact the makers of SexyBookmarks and Viper's Video Quicktags and see if they can fix the issue.
If you could give me access to your blog so I could try this then I could give you a more specific description of exactly how those other plugins are changing that content.