When I post a video in an article it appears in the correct position but when I look at the same article in a section blog layout or a category blog layout the video appears half-off the edge of the screen and not inline (it sits on top off the following post).

The same problem occurs with both youtube and vimeo clips.  Does this problem crop up a lot of is it likely to be template-related?

Could you provide a link to your site?

Thanks for the quick reply.  I've resolved the problem, sort of.  I installed instead the plugin AV Reloaded (it uses the same insertion code, more or less) and this produced the problem of an incorrect Flash warning appearing beneath the video – googling a solution, I put the code in a div and this stopped the problem.

I think that the fact I had problems with both plugins might suggest a deeper problem with my template (which I had customised).