We just upgraded the forum software to a completely new version so you will see some changes. We are still working through some final tweaks so let us know if you see anything odd.
When trying to post a picture this morning I noticed it only saves it as a attachment. Before you had the option for full scale or thumbnail. I did not see this option this time.
Use the "insert image" button in the toolbar. Just tested it. The interface is a bit different but it still gives the same options. The "attach files" button is for other file types I suppose.