I am using lightbox 2.0 from http://www.m3nt0r.de/blog/lightbox-wordpress-plugin/ just install it and activate plugin .. follow the readme and do what I said with the clicking on the pictures.. it Should work if it doesnt . .. ? I dont know?
I had a few issues at first but it wasnt broken.. when you upload the file and then browse the that photo, if you click on the photo you get a little menu option like Use Thumbnail or No Link… If you click on those they change your options I set mine to Link to Picture and use thumb nail and if started working for me. Hope that helps