Google Not reading my Links

Why?

[dinnerware]

I have been in the process of developing a "PR" for my site and I have traded links with a few sites and although most of my link trades have been from PR4s I have been unable to move of the PR0. I have another site (unrelated) that was able to simply get one PR5 link (at the same exact time as my other link trades) and just got a PR4 rating (previously PR0) So...any thoughts/input on why this is not getting better. Is it possible Google has just not found the links from the other sites to mine or is there a problem I am overlooking?
ADDITIONAL INFO: The total # of links is 7 mostly from PR4s.

[Emma McCreary]

if Google has not crawled either those links or your website, you would still have a PR0.

Do those links show up in a google search for them?
link:www.your-site.com

Does your site show up when you search for just your domain?
www.your-site.com

[Dreamquick]

Lots of people have suggested in the past that the "link:" method only shows up linked sites with a PR >= 4 - but I'm not 100% sure about this.

Also you potentially might have gotten a link off a page which wasn't really a PR4 but which had a "guessimate" of PR4 according to the toolbar - which is known to guess the rank when an absolute answer for a page is not known.

Are you sure these are links which Google can follow? (Check out [webmasterworld.com...] for some interesting reading on this subject)

If it was me my first stop would be to look at who *I* was linking to (to ensure that I wasn't linking out to "bad neighbourhoods" which could hurt my ranking) plus it allows you to check that a site which was great a year or more ago is still a useful site for me to link to.

- Tony