You will recall I was having problems posting pictures. Some people could see them, but most could not.
It appears that the cause may have been that Picasa (whose web albums I was using) conflicted in some way with the PPrune picture hosting. On some occassions pictures posted fine, but within the last week or so the original problem reoccurred whereby the URL of the picture changed after posting or in preview mode, with the result that no-one could see my pictures.
So have taken Mike's advice and now use Virgin Photobucket, which seems to work fine.
If anyone out there has experience with Picasa and has experienced a similar problem (and resolved it!) I would like to hear from them.
Thanks
Ken