Image popup on link mouseover

Hello,

I’ve been looking for a plugin to image popup on link mouseover, something link a preview image when hovering link.
Finally found something that results here: http://planetozh.com/blog/my-projects/wordpress-plugin-avatar-gravatar-popup/
And it works with 3.4.1, but i can’t change image size as 80px is really small. Tried to change on php file to a bigger size as instructions but nothing changes.

Anyone can help?
Or suggest any similar plugin to use?
Thanks