NextGen Gallery eliminate displayed error messages

Using the NextGen Gallery Plugin…when it cannot find the image it is looking for it displays an error message, which is generated as an image. I think the message itself may vary, but here is what I’ve seen for the message “Error: File Not Found”:

The Error Image

I want to eliminate these error messages — or at least keep them from displaying or hide them when they do occur.
I believe I found the code that calls these messages in the ImageMagick files within the NextGen Gallery Plugin folder. I may be able to pull that code from the plugin, but I don’t want to do that. I’d like to find another solutions, either by adding some function to my theme’s functions.php or using or jQuery. The problem is that when this message/image gets displayed, the URL is still the same as when it finds the image, so I don’t see any way to target the image and hide it ONLY when the error message gets displayed.
What I’d like to do is use a function in functions.php to somehow intercept the code that tells NGG/ImageMagick that the image is missing, so I can use it as a conditional to prevent the image from displaying if it is not found.

The code I’m using is adapted from code I found somewhere (sorry, don’t remember exactly where) that allows for random display of an NGGallery image. I’m using it as a CSS Background image. Here is my code at pastebin:

NextGen Random CSS Background

Somewhere in this code I want to be able to add a conditional that basically says:

IF THE IMAGE IS NOT FOUND, WHICH CAUSES THE ERROR MESSAGE TO FIRE, THEN RETURN “style=’background-image: none;’

Anyone have any ideas how this might be accomplished without modifying the plugin files?

Thanks.