When you share the album, be sure to check off the option 'allow viewers to download'. If you did NOT make that selection, then the viewer would be restricted from being able to get to the larger sizes (which it sounds like is happening).
The end-users were allowed to download images.
I tested the following procedure which many not be optimal but is sufficient to resolve the issue:
1) I send the end-users a web pointer to a specific album which has them start with GRID.
2) They select a particular photo that they want to either save to disk and email later or set as their as their computer screen background.
3) When a full size image appears (in slideshow mode) they right click to either "Save Picture As' and/or "Set as background"
The test was done with a 2688 x 1844 image which was reduced to a 1024 x 702 image when using "Save As" which is sufficient for email. I also tested the same image as a background and it was visually sufficient. The problem before was that end-users and myself were performing "Save As" on images that were on the slide strip which are just small sized thumbnails.
Thanks for replying.
When your visitors go into a shared album, they should be able to click on a single photo, and it should come up full screen (with the filmstrip of other images along the top).
At the bottom/left the download and print buttons should (conditionally) appear; looks like this:
Clicking on that button should allow the user to download the full resolution image, not just the larger size that we use for screen display (which is what your process accomplishes).
Is this workflow working for you?