the reson for "Anti-IFRAME Protection" is :
- Google no longer uses the iframe
- Bing will detect if you're using js busted frame and you will not show at all in the iframe ... never
- Yahoo and Bing is low source trafic for images, I know this from my experience (I do not know in your case).
So, for google and bing, JS ifrae-busted is totally useless !!!
If you have not seen this on bing, you'll surely notice them soon.
Manualy disable "Anti-IFRAME Protection" and will work.
I still think if I change or not default behavior to Disable !!! (For me "enable" it is the best way)
Yahoo does not offer link over images !!! unfortunately ... but I have some idea :) of displaying an arrow to bottom-left to redirect user attention to the link from bottom.
But that would mean additional cache to store images separately for yahoo.
I do not know if it's worth to much effort and resources for yahoo.
On BING is posible, but your server load increases 3 times!
For 3 times successively bing trying to load an image that is redirected to a html page. The reason is that the new image url can not be displayed in IMG html tag.
Reason is that the image redirection is done immediately after search page is loaded ... because the redirection condition from plugin !
And if redirection is active, watermark not shown, because no longer loaded in the browser.
Possibilities exist but involve major changes and potential excessive use of the database.