Fixed up some errors and do the guid cache fix on the module instead of backend coz that would cause other issues.

src/NzbDrone.Api/Indexers/ReleaseModule.cs

@@ -53,7 +53,7 @@ namespace NzbDrone.Api.Indexers
 
         private Response DownloadRelease(ReleaseResource release)
         {
-            var remoteEpisode = _remoteEpisodeCache.Find(release.Guid);
+            var remoteEpisode = _remoteEpisodeCache.Find(GetCacheKey(release));
 
             if (remoteEpisode == null)
             {
@@ -113,8 +113,14 @@ namespace NzbDrone.Api.Indexers
 
         protected override ReleaseResource MapDecision(DownloadDecision decision, int initialWeight)
         {
-            _remoteEpisodeCache.Set(decision.RemoteEpisode.Release.Guid, decision.RemoteEpisode, TimeSpan.FromMinutes(30));
-           return base.MapDecision(decision, initialWeight);
+            var resource = base.MapDecision(decision, initialWeight);
+            _remoteEpisodeCache.Set(GetCacheKey(resource), decision.RemoteEpisode, TimeSpan.FromMinutes(30));
+            return resource;
+        }
+
+        private string GetCacheKey(ReleaseResource resource)
+        {
+            return string.Concat(resource.IndexerId, "_", resource.Guid);
         }
     }
 }

src/NzbDrone.Core.Test/IndexerTests/TorrentRssIndexerTests/TorrentRssSettingsDetectorFixture.cs

@@ -254,10 +254,8 @@ namespace NzbDrone.Core.Test.IndexerTests.TorrentRssIndexerTests
         }
 
         [TestCase("BitMeTv/BitMeTv.xml")]
-        [TestCase("Fanzub/fanzub.xml")]
         [TestCase("IPTorrents/IPTorrents.xml")]
         [TestCase("Nyaa/Nyaa.xml")]
-        [TestCase("Omgwtfnzbs/Omgwtfnzbs.xml")]
         [TestCase("Torznab/torznab_hdaccess_net.xml")]
         [TestCase("Torznab/torznab_tpb.xml")]
         [TestCase("Torznab/torznab_animetosho.xml")]

src/NzbDrone.Core/Indexers/IndexerBase.cs

@@ -74,7 +74,6 @@ namespace NzbDrone.Core.Indexers
 
             result.ForEach(c =>
             {
-                c.Guid = string.Concat(Definition.Id, "_", c.Guid);
                 c.IndexerId = Definition.Id;
                 c.Indexer = Definition.Name;
                 c.DownloadProtocol = Protocol;