Google has a special way of showing backlinks, basically only showing a tiny subset.
I find doing a search for backlinks at Yahoo, will tend to show a more comprehensive.
I believe google uses their toolbar information to show you what they want. So, when i looked up a site of my with 150,000+ back links, google showed me 45 back links, someone who didn’t check my back links often/ever, saw 50,000 back links from google but we both saw 150,000+ in yahoo.
So, check different SEs for a more accurate backlink report.