I am using getFullImageURL() in my templates to display the full sized image.

By default, this shows the original image from the /albums/ directory.

Checking the [i]cache full sized[/i] option in Admin > Option > image does not change this: the original image is still displayed (is this normal?).

Selecting the [i]protected view[/i] from the dropdown menu has the following effect:

[list]
[]when the image is uncached, it displays an "ugly" URL like:
http://www.france-in-photos.com/zp-core/full-image.php?a=alps/haute-savoie/chamonix-valley&i=chamonix-4-2.jpg&q=75&wmk=!&dsp=Protected%20view&check=bcf98c0ca2648deec4224592d3df1b7035b67dbb
[]as soon as the page containing the image has been loaded, the image URL becomes :
http://www.france-in-photos.com/cache/alps/haute-savoie/chamonix-valley/chamonix-4-2_FULL.jpg

[/list]
The problem is that Google does not like the "ugly" URL.
(the image link is broken)
These images thus cannot be indexed in Google images.

Is there a way to ensure that the cached image URL is displayed every time, even at first page load?

Checking the cache full sized option in Admin > Option > image does not change this: the original image is still displayed (is this normal?).

The descriptions tell you that this option does nothing unless the protect full image option is also set.

To pre-cache the full images you will need to add an image cache size to the cacheManager plugin and run the cache manager cache the images function. F0r the size part of the cache size simpley type
"FULL"

Thanks for your prompt reply, sbillard. I took a look to the cache manager plugin and the full image size already appeared.
I have done the caching process on one website and it seemed to work fine.
Now waiting for Google to index the images.