Certain log messages didn't include the exception.

src/NzbDrone.Core/Datastore/Database.cs

@@ -50,7 +50,7 @@ namespace NzbDrone.Core.Datastore
             }
             catch (Exception e)
             {
-                _logger.Error("An Error occurred while vacuuming database.", e);
+                _logger.ErrorException("An Error occurred while vacuuming database.", e);
             }
         }
     }

src/NzbDrone.Core/HealthCheck/Checks/DownloadClientCheck.cs

@@ -35,7 +35,7 @@ namespace NzbDrone.Core.HealthCheck.Checks
                 {
                     var message = String.Format("Unable to communicate with {0}.", downloadClient.Definition.Name);
 
-                    _logger.Error(message, ex);
+                    _logger.ErrorException(message, ex);
                     return new HealthCheck(GetType(), HealthCheckResult.Error, message + " " + ex.Message);
                 }
             }

src/NzbDrone.Core/Messaging/Commands/CommandExecutor.cs

@@ -53,7 +53,7 @@ namespace NzbDrone.Core.Messaging.Commands
             }
             catch (Exception ex)
             {
-                _logger.Error("Unknown error in thread: " + ex.Message, ex);
+                _logger.ErrorException("Unknown error in thread: " + ex.Message, ex);
             }
         }
 

src/NzbDrone.Core/Metadata/Consumers/Xbmc/XbmcMetadata.cs

@@ -335,7 +335,7 @@ namespace NzbDrone.Core.Metadata.Consumers.Xbmc
             }
             catch (Exception ex)
             {
-                _logger.Error("Unable to process episode image for file: " + Path.Combine(series.Path, episodeFile.RelativePath), ex);
+                _logger.ErrorException("Unable to process episode image for file: " + Path.Combine(series.Path, episodeFile.RelativePath), ex);
                 
                 return new List<ImageFileResult>();
             }