After installing plugin Google Doc Embedder, version 2.4, the insertion of JPG and PNG images via WordPress editor gives the following error:
"image/png not a value in supported_exts"
As this problem didn't happen before activating Google Doc Embedder and doesn't happen after deactivating the plugin, I suppose it has to do with it.
In fact, the situation is quite tricky: if I re-activate the plugin after publishing the post, the PNG inserted is shown. In case you can see the site, here you have the URL: http://dpto.educacion.navarra.es/blogpnte/, and the post concerned, http://dpto.educacion.navarra.es/blogpnte/2012/05/03/presentacion-juego-gurbinjuego.
Any idea will be welcome.