Okey, problem solved.
We have seen the new "copy" option to the image.reset function and the attribute is now preserved.
Here is the current code:
Code
image.reset("copy");
set(image.sphere.url, get(image.imgalt));
loadpanoimage(KEEPPLUGINS|KEEPVIEW);
Thanks for your replies, hope this can help someone in the future and we hope we don't need to use more this thread, that will be good news.