We have a recent Sharepoint Foundation 2010 installation that is working fine except for searching. When you search as a site collection administrator, everything works perfectly and results are returned as expected. When you search as anyone else, be it a visitor with limited access or a site administrator, it returns no results.
There aren't any errors in the event log and Sharepoint seems to think its doing what I want it to do, but I can't seem to find any permissions anywhere that might be causing this issue.
What could be causing this issue?