Gallery Popup problem: image displayed *very small* every now and then

[fabie]

We are experiencing the above error currently in the Fickr module but it seems that other users http://www.silverstripe.com/site-builders-forum/flat/60384?showPost=62001 are experiencing it in the standard silverstripe gallery module as well. It seems to be linked to the Javascript popup.

We have documented what happens here: http://bottlebrush.net.au/ss-lightbox.png

One of our client has also reported that sometimes, when the image thumbnail is clicked, the Javascript popup does not work at all and the image is simply opened in another browser's window.