Hi Paul,
I had a look at the source html of your post and it seems you are posting the URL of the viewing page, rather than the URL of the direct image. In Imageshack, you will see two URLs under 'Links to share this image', one is called 'Link' and one is called 'Direct'. You need to use the 'Direct' URL for an embedded image.
For example, using the two URLs for your first image:
Using
http://imageshack.us/photo/my-images...12020647z.jpg/ you will get:
as an embedded image. E.G. Nothing.
Using
http://img836.imageshack.us/img836/9...312020647z.jpg you will get:
Hope that helps.
Just edit your post and use the 'Direct' URL and you should be fine.
EDIT: You should be able to delete a post when in Edit mode - Along the bottom right, you should have 'Save' 'Go Advanced' (always been to scared to press that one in case I find myself out of my depth) 'Delete' and 'Cancel'.