First, thanks to TurbineRepair for highlighting this problem
coating-failure-t-866.html
I think there is a problem with an old forum plugin misbehaving. Unfortunately, not an easy fix, but one I will be attempting soon.
In the mean time, if you experience a problem uploading an image/attachment and get an error message or a blank white page - refresh/reload page - (go back one or more pages if post edit page does not appear and refresh page) and then hopefully you should see the file has actually uploaded and just needs adding to your post as screen shot below (ignore any further error messages).
If this does not work for you, make your post and just email your image /attachment to
me and I will put it into your post for you.