Hi Clive,
I think you have to be a paid member to upload to the gallery. It is pretty cheap. Have a look here for more info. LINKY
Not sure about Picasa but when you put the image url in the box, does it refer to the actual image and ends with the image extension. For example
http://www.blah/blah/xyz123/image.jpg
[/CODE]
So the last part of the URL shows that it is an image. The boarad seems to be happy with most common extensions (jpg png gif etc).
If you use Firefox as a browser, where your image is show on a web page, right click and chooose "copy image location". come back to the board and then try to post an image by bringing up the "image" box and pasting the link into the box. I always use the full [CODE]
Http://www............... when posting images.
I hope this helps and solves your problem.