Last night I tried to post the thread again and after eight attempts I realized that the link I was trying to post was the problem. ie: every time I used the link the whole post got deleted. If I started a thread with out the post it worked, but if I then edited it to include the link the whole thing vanished again. At one point I got a message saying the post had been marked as spam?
Eventually I gave in and just posted with out the link. This morning a post WITH a link has appeared but it seems to have been submitted after I had gone to bed!