Using the available configuration options, it is not possible to have the caption line up with the left-hand edge of each main image outside the image.
However, you could use captionPosition="OVERLAY_TOP" or captionPosition="OVERLAY_BOTTOM" in conjunction with showOverlay="ALWAYS" in order for the caption to line up with the left-hand edge of each main image inside the image and always be displayed without the need to hover over the image.
You could also try using the above suggestion in conjunction with a negative value for captionPadding, though this will move the caption in both the x and y dimensions by the allotted pixel value so the caption will not line up with the left-hand edge of the main image but will be the same distance away from the left-hand edge no matter what orientation the image is. Also, please bear in mind that SimpleViewer was not designed with this usage (ie. negative values for options) in mind.

You could try my suggestion above but, alternatively, instead of trying to realign the caption, you could justify the image to the left margin of the image area by using imageHAlign="LEFT". In doing so, the left-hand edge of each main image will always be in the same place (as will the caption).
You could also use the imageVAlign option to ensure that a corner (rather than just an edge) of each main image is always in the same place.
Descriptions of these options can be found in the Main Image section of the 'SimpleViewer-Pro Config Options' page.

Here's an example of my current config:

http://www.newperspectivefilms.com/phot … /landscape

It's only a small issue concerning the caption distance from the top of the image (specifically in fullscreen).  Otherwise, I'm loving the product!

thanks

To 'stick' the caption to the bottom of the image, try these config option settings:

captionPosition="BOTTOM"
lockBottomStack="false"