Sitelinks, the results on Google that appear for some searches showing multiple pages on your site, can sometimes show strange results. Google controls the links that appear in these sitelinks and you have little control over them. Fortunately, Google Webmaster Tools provides some control over these results.
For one blogger at SEOMoz, the sitelinks were causing some unexplained behavior in one geographic location. Check your search results to see how Google treats your search positions in sitelinks.