Who Links To You?

Ever notice how Google's "link:" command doesn't return comprehensive results for those pages that link to the page you enter? For instance, say I want to know which web pages are linking to my web site. I enter [link:http://www.infoworks1.com/] and it says there are 25 pages that link to my site, and it displays about 20 of them as some are repetitive. However, I know that there are other links from other sites that link to me (legitimate sites and legitimate links). A better way to find out who links to you is to use the same query on alltheweb.com. In this case, entering the query [link:http://www.infoworks1.com/] reveals there are 218 pages linking to my site and it shows 34 of them -- including those links I expect to see from sites I know link to me. Can anyone shed light on this? Is there are reason Google is ignoring some of the sites?