Wedge,
clicking on the attachment icon (paperclip) will bring up a dialog box that tells you what program you are using to open the .jpg file. If you do not have a utility to view .jpg files then it will not be viewable.
I use Irfranview to view them. Very versatile program and it is free.
As for the .jpg screen shots not showing as pictures on your computer when you view the post I'm not sure exactly would be the cause but somewhere in the dark halls of memory Java comes to mind but perhaps somebody more technically oriented than I can shed some light on the problem. Also, are you logged onto the forums per corbu1's post?