diff --git a/lib/geocoder/lookups/maxmind.rb b/lib/geocoder/lookups/maxmind.rb
index 0be2495cce438bcfb8afe1cc7ae1bb15c0deefc8..7e67fae8967a5630ee9ebc1bc81f64f6d502b140 100644
--- a/lib/geocoder/lookups/maxmind.rb
+++ b/lib/geocoder/lookups/maxmind.rb
@@ -15,9 +15,12 @@ module Geocoder::Lookup
 
     private # ---------------------------------------------------------------
 
-    def service_code
+    ##
+    # Return the name of the configured service, or raise an exception.
+    #
+    def configured_service!
       if s = configuration[:service] and services.keys.include?(s)
-        services[s]
+        return s
       else
         raise(
           Geocoder::ConfigurationError,
@@ -28,6 +31,19 @@ module Geocoder::Lookup
       end
     end
 
+    def service_code
+      services[configured_service!]
+    end
+
+    def service_response_fields_count
+      Geocoder::Result::Maxmind.field_names[configured_service!].size
+    end
+
+    def data_contains_error?(parsed_data)
+      # if all fields given then there is an error
+      parsed_data.size == service_response_fields_count and !parsed_data.last.nil?
+    end
+
     ##
     # Service names mapped to code used in URL.
     #
@@ -45,7 +61,7 @@ module Geocoder::Lookup
       return [reserved_result] if query.loopback_ip_address?
       doc = fetch_data(query)
       if doc and doc.is_a?(Array)
-        if doc.last.nil?
+        if !data_contains_error?(doc)
           return [doc]
         elsif doc.last == "INVALID_LICENSE_KEY"
           raise_error(Geocoder::InvalidApiKey) || warn("Invalid MaxMind API key.")
diff --git a/lib/geocoder/results/maxmind.rb b/lib/geocoder/results/maxmind.rb
index 2cc45beba872469199bdb372feb38529ad75fe01..aa6c7aa92b2cafaa63c83aff6f6f6abec7f7d421 100644
--- a/lib/geocoder/results/maxmind.rb
+++ b/lib/geocoder/results/maxmind.rb
@@ -71,7 +71,7 @@ module Geocoder::Result
     #
     def service_name
       self.class.field_names.to_a.each do |n,f|
-        return n if f.size == @data.size
+        return n if (@data.size..@data.size+1).include?(f.size)
       end
       nil
     end
diff --git a/test/fixtures/maxmind_24_24_24_21 b/test/fixtures/maxmind_24_24_24_21
index 3fde71520e063734d3ab96fc09afb5c8d3e7aa3f..f4cd62e01d3d617a216c8f5b6af90b313636da09 100644
--- a/test/fixtures/maxmind_24_24_24_21
+++ b/test/fixtures/maxmind_24_24_24_21
@@ -1 +1 @@
-US,
+US
diff --git a/test/fixtures/maxmind_24_24_24_22 b/test/fixtures/maxmind_24_24_24_22
index 426280ed25a5e0ccd3d2b83c0daf4981424f69b3..b9aee130e818f620dea7edc6ce110478578ab20c 100644
--- a/test/fixtures/maxmind_24_24_24_22
+++ b/test/fixtures/maxmind_24_24_24_22
@@ -1 +1 @@
-US,NY,Jamaica,40.6915,-73.8057,
+US,NY,Jamaica,40.6915,-73.8057
diff --git a/test/fixtures/maxmind_24_24_24_23 b/test/fixtures/maxmind_24_24_24_23
index 8ffaf07f09855cf9b27aea3dbb3e0901e664152c..29ecfb21b570c06c82348010be3f055d60f5bbb1 100644
--- a/test/fixtures/maxmind_24_24_24_23
+++ b/test/fixtures/maxmind_24_24_24_23
@@ -1 +1 @@
-US,NY,Jamaica,,40.6915,-73.8057,501,718,"Road Runner","Road Runner",
+US,NY,Jamaica,,40.6915,-73.8057,501,718,"Road Runner","Road Runner"
diff --git a/test/fixtures/maxmind_24_24_24_24 b/test/fixtures/maxmind_24_24_24_24
index ab20e03758da5e155758065df679c5d682c8106c..14939030ea18388814557a2ffa162beab75ea6f1 100644
--- a/test/fixtures/maxmind_24_24_24_24
+++ b/test/fixtures/maxmind_24_24_24_24
@@ -1 +1 @@
-US,"United States",NY,"New York",Jamaica,40.6915,-73.8057,501,718,America/New_York,NA,,"Road Runner","Road Runner",rr.com,"AS11351 Road Runner HoldCo LLC",Cable/DSL,residential,779,99,37,76,,
+US,"United States",NY,"New York",Jamaica,40.6915,-73.8057,501,718,America/New_York,NA,,"Road Runner","Road Runner",rr.com,"AS11351 Road Runner HoldCo LLC",Cable/DSL,residential,779,99,37,76,35
diff --git a/test/test_helper.rb b/test/test_helper.rb
index b3aa68f21dcfcb06b4117e8faed1bc6e04bf507f..b74017d41d0d497d8b61b60ea933e452613cf452 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -239,7 +239,7 @@ end
 class Test::Unit::TestCase
 
   def setup
-    Geocoder.configure(:maxmind => {:service => :omni})
+    Geocoder.configure(:maxmind => {:service => :city_isp_org})
   end
 
   def teardown