added Opera note

README.md

@@ -27,6 +27,7 @@ I have written about this technique in 2008 [when I brought CSS transforms to br
 ## Caveats
 
 - __Internet Explorer is not supported__, as it doesn't support the foreignObject tag in SVG.
+- For whatever reason, Opera is failing. I am not sure why. If a Opera pal is reading this, get in touch!
 - SVG's foreignObject is subject to strong security – meaning any external content will likely fail (i.e. iframes, web fonts)
 - The DOM object is __not linked, but copied__ – if you change the style of the DOM object, it will not automatically update in Canvas
 - Content outside the bounding box of the element will be cut of per default if painted to Canvas. Don't worry though, simply pass a more confortable offset to the toImage function (see above)