When using the "Circle Locator" I encountered the following error.
user warning: Column 'nid' in field list is ambiguous query: SELECT COUNT(DISTINCT (nid)) AS count FROM node n INNER JOIN location l ON n.vid = l.eid INNER JOIN node_access na ON na.nid = n.nid WHERE (na.grant_view >= 1 AND ((na.gid = 0 AND na.realm = 'all') OR (na.gid = 0 AND na.realm = 'og_public') OR (na.gid = 1 AND na.realm = 'term_access'))) AND ( l.type ='node' AND l.latitude > 39.9024553097 AND l.latitude < 40.6263226903 AND l.longitude > -77.2772947173 AND l.longitude < -76.3286652827 AND (IFNULL(ACOS(0.763070181095*COS(RADIANS(latitude))*(0.228300233173*COS(RADIANS(longitude)) + -0.97359077827*SIN(RADIANS(longitude))) + 0.646315633977*SIN(RADIANS(latitude))), 0.00000)*6369177.89072) < 40233.68) in /home/spiralscouts.org/public_html/includes/database.mysql.inc on line 172.
To reproduce this error click on "Circle Locator", then on the search by Zip code link. I entered my zip code (17111), and the page returned had that error.
The above error is relatively easy to fix, I believe it should be "SELECT COUNT(DISTINCT (n.nid))". Having worked with Drupal in the past the hardest part is finding the file which this query came from.
If you have any questions regarding this ticket, please feel free to contact me fizz@beyond.hjsoft.com