Strange FLVPlayback problem

Ok, this is really frustrating. I used the FLVPlayback component to make a stream (from FMS) and it all works fine, even accepts variables passed from good old FlashVars. But then when I introduce it into the site environment it doesn’t play. The swf loads, the vars are passed (tested with a simple dynamic textbox) but the component just doesn’t load. - Working standalone example.

But then in the main site environment using the exact same swf, same embedding technique etc.:

Any ideas?