Can't crop

I just installed the module, and really apreciate that the image is now in a new tab, really makes sense !
But when uploading a new image, the image preview correctly, but there is no cropping function going on..

I have firebug reporting an error :

Event.observe is not a function

So I guess it's not finding the script...

Also, like the original cropper, will it be possible to set min width/height ?... and even better... max width/height ?
Or could it use image cache to scale and re-crop the user croping for a better concistency on the website ?

Thanks !