Fix youtube embed in tinyMCE editor mod

Im after someone who really knows what they are doing with the tinyMCE editor to get a free mod working properly for me.

I have a pretty new 6.0003 Dolphin/Ray installation on a Host4Web server installed by Boonex. Its running pretty good now that Ive fixed a few quirky things :-)

I really want to be able to embed youtube videos in profile, forum, blogs, mail, etc. I tried installing the free youtube mod Add Youtube to Editor for tinyMCE.
I even got it to correctly embed one video in a blog - but I cant do it again. The maker of the mod was very helpful but decided it was something new in the Dolphin installation that was not working.

However, other people say they have the mod running with the latest Dolphin version okay.
The little embed icon shows up properly in all the editors for the various types of posts. Its got to be some simple thing to fix if you know enough to find out what it is :-)

So the job is to figure out what the problem is and get the mod working properly.
Getting 'safe html' working at the same time would be an added bonus!

If recommended I would install the very latest update package first.

I cant afford to spend much on this at the moment so I really need someone who knows tinyMCE well enough to figure out why its not working.

Thanks