iPhoto 'publish' option grey-ed out - help!

Hi,

I'm trying to upload an album to Facebook but the 'publish' option is greyed out.

I clicked change account to ensure it's ok from the facebook end of things and that's fine but still won't let me publish when I try again.

It's iPhoto 9 (version 8.1.2), and my mac is OS X 10.6.8 and I've checked all software up to date.

Can somone help me?

Thanks