I have 2 months old page for selling my shareware and freeware. I am registered on a lot of directories with sharewares and some of them use static back links on my pages. When I was looking with link: command on other search engines I found about 600 back links on my pages. But in in Google still nothing. My PR is still 0, but I as read before I must wait for PR recalculating it is OK, but what is it with back links in Google?
If I knew the answer to your question I would be a billionaire. Don't worry though, I'm still poor, and I am also going through the same experience, so I'll just be patient and wait it out. I suggest you do the same.
Google doesn't show all the back links, only the ones that it wants to. I couldn't find the site, but Matt Cutts was talking about it, and another SEO I forget. Anyways, it's the quality of link, not quantity. I put up a site 1.5 weeks ago, it got indexed and now ranks #1 for the keyword I selected. Funny thing is, the website is only like 5 pages.
Do not focus too much on how many backlinks Google shows. Although we all still look at the Google link: command, it really does not tell the whole story. One theory is that Google will only show links it finds relevant but we have many examples where this is not true. For example, we have sites that have been listed in the proper ODP (indexed) directory for a year and Google still does not recognize the backlink!