>Yes 4eyes, it's from the tool bar(PR0).
Dan, how about the rest of the site - is it also PR0, except for the homepage? And is the page that'll be linking to you part of a "directory" on the site that's all PR0?
>How can I verify if it's the correct PR?
There's no way to verify it exactly. If it's been up a while, you can assume it's reasonably close.
If it's brand new and not indexed yet, it's a toolbar guess. However, I just checked only two PR5 sites that each have pages that are brand new that haven't been indexed yet, and for those pages the toolbar guess is PR3 (based on the PR5 of the homepage most likely).
So the PR0 value back to you of that page you're looking at is highly questionable, and it's not impossible that it's one that's been penalized in recent months - some have had PR to the index page restored and internal pages still retain the PR0 penalty. Without any way to verify whether it's a penalty, and as of now no PR benefit back to you, I'd personally pass on it unless it would have tremendous value to site visitors. And even then, it might be wise to think twice, especially if your site is new with little to counter-balance linking into what could be a bad neighborhood.
Google doesn't counsel us which individual sites to link to or not, but we have been warned about linking into bad neighborhoods, and we've got enough information to be able to exercise caution, which I'd do in this case.