Display Previous/Next links on gallery attachments

I'm using Atahualpa 3.3.3 on WP 3.0.1

When individual gallery attachments (eg: photographs) are displayed in some themes, they are full-size and there are Previous/Next links added below them.

I would like Atahualpa to do this.

I have tried adding an image.php template which works in other themes, but the php stops rendering anything at the point it calls ft_previous_image_link. It does show the photo full-size.

I next added the attachment.php from the 2010 Theme - this also shows the photo full-size, and adds working links to the next attachment, but the php again stops abruptly soon after this.

Am I on the right track here?

Am I missing anything?

Any advice would be appreciated.