extensions.joomla.org/extensions/photos-.../photo-gallery/10809

This extension works in the articles that simple image gallery did not.

Check your HTTP Server confguration to know if you are using the correct "document root".

We have retested and we can confirm it is working perfectly.
We have created a master with an SIG in a directory and a slave with the SIG into another images subdirectory. Everything is working fine.
Review your HTTP server configuration.

I'm happy with ppgallery, it offers option to include txt file with image descriptions and different styles of lightbox.

My next question is about inserting images into article shared across many web sites. I know it can be done with link to images stored on another webpage

<img src="www.cfsports.co.uk//images/midi/midi_cf%...0thumbnail.jpg" width="250" height="150" border="2" alt="picture of cricket bat!" />

Can it be done using an editor and not going into the source html ? taking link to images folder and propagating it to jms shared articles.

This mainly related to the editor.
Most frequently, the editor detect the domain on which you are working and remove the "aboslute" ..... value to keep a relative location.

If you have share the images folder, this is not a problem.
If you have specific image folder, you generally need to provide a full path or a link to a speicifc directory where you would have stored the "shared", "common" images across websites

Am I trying to achieve something that is not possible - master or slave site with independent image folder sharing articles including simple image gallery with another slave site.

The error message I get on slave site from master site shared article is

Warning: opendir(htdocs/njrpartnership/jms_trade/jms_icingp/images/stories/floorcraft) [function.opendir]: failed to open dir: No such file or directory in /homepages/33/htdocs/njrpartnership/multisitecf_v1.0.2/plugins/content/jwsig.php on line 100

(removed database ref)

images working fine in SIG on master site article.

As explained several times, check the HTTP configuration and the setup of JMS.
If you want to have specific images directory, see the procedure described in the video CP-05.

The key element is that you setup your HTTP Server correctly to assign the domain or subdomain with the correct "document root".

I think that you have deployed the slave site into a specific directory but NOT have used the same path in the HTTP Server. Probably you have assigned the master "document root" directory and not the specific slave site directory.

So check that you have deployed the slave site into a specific directory and that you have created a speciic images folder.
Check that your slave domain or subdomain defined in your http server is configured with the specific directory