The front ring on my Canon SX400 keeps popping out when I take my Macro lens off, and it's making me nuts, I feel like that ring is going to break one of these days... there appears to be some blue rubber cement/glue that was holding the ring in, and I'd like to purchase that same glue to repair it, does any one know what glue is good to fix this problem? I don't want to use the wrong kind and damage my lens. I tried Google, and it keeps bringing up superglue, and I'm not real confident that the vapors from that would be ok for the camera lens. Thanks for any help!!