I’ve installed a plugin to allow authors to embed videos into their posts. Don’t use the ‘embed’ code given on the videos, instead use this special markup syntax:
[site id]
Make sure you are working in the ‘HTML’ editor when writing your post. Get the ID for the video of your choice, and precede it by the video’s host. Example of a youtube video:
[youtube 8DHOZW_80Pk]
or a Vimeo video:
[vimeo 138920]
Make sure you read this site for the full instructions.