Trust me Steve, use the postimgs link. Once you upload the pic, just click the share button and copy/paste the DIRECT LINK. Make sure you have the [img]and[/img]
If you go to Use Full Editor for the reply, you can use the Insert Image Link 'button'. It looks like a scenery picture (next to the Happy Face). Once you click it you can just paste your link in the box and it automatically adds the [img] and [/img]