Index: fb_user.module
===================================================================
--- fb_user.module	(revision 3970)
+++ fb_user.module	(working copy)
@@ -807,11 +807,13 @@
   if ($fbu &&
       $account->uid != 0) {

+    // Note, use %s for bigint field fbu.
+
     // Delete any pre-existing mapping that might exist for this local uid or fbu.
-    db_query("DELETE FROM {fb_user} WHERE uid=%d OR fbu=%d", $account->uid, $fbu);
+    db_query("DELETE FROM {fb_user} WHERE uid=%d OR fbu=%s", $account->uid, $fbu);

     // Create the new mapping.
-    db_query("INSERT INTO {fb_user} (uid, fbu) VALUES (%d, %d)", $account->uid, $fbu);
+    db_query("INSERT INTO {fb_user} (uid, fbu) VALUES (%d, %s)", $account->uid, $fbu);

     if (fb_verbose()) {
       watchdog('fb_user', 'Using fb_user to associate user !user with facebook user id %fbu.',
@@ -940,7 +942,7 @@
 }

 function _fb_user_get_uid($fbu, $fb_app = NULL) {
-  $result = db_result(db_query("SELECT uid FROM {fb_user} WHERE fbu=%d", array(
+  $result = db_result(db_query("SELECT uid FROM {fb_user} WHERE fbu=%s", array(
                                  $fbu,
                                )));
   return $result;