diff --git a/happstack-server.cabal b/happstack-server.cabal
--- a/happstack-server.cabal
+++ b/happstack-server.cabal
@@ -1,5 +1,5 @@
 Name:                happstack-server
-Version:             7.3.4
+Version:             7.3.5
 Synopsis:            Web related tools and services.
 Description:         Happstack Server provides an HTTP server and a rich set of functions for routing requests, handling query parameters, generating responses, working with cookies, serving files, and more. For in-depth documentation see the Happstack Crash Course <http://happstack.com/docs/crashcourse/index.html>
 License:             BSD3
diff --git a/src/Happstack/Server/Internal/Handler.hs b/src/Happstack/Server/Internal/Handler.hs
--- a/src/Happstack/Server/Internal/Handler.hs
+++ b/src/Happstack/Server/Internal/Handler.hs
@@ -2,7 +2,7 @@
 
 module Happstack.Server.Internal.Handler
     ( request
-    , parseResponse 
+    , parseResponse
     , putRequest
     ) where
 
@@ -32,6 +32,7 @@
 import Happstack.Server.SURI(SURI(..),path,query)
 import Happstack.Server.SURI.ParseURI
 import Happstack.Server.Internal.TimeoutIO (TimeoutIO(..))
+import Happstack.Server.Internal.Monads (failResponse)
 import qualified Happstack.Server.Internal.TimeoutManager as TM
 import Numeric
 import System.Directory (removeFile)
@@ -84,7 +85,7 @@
                      let ioseq act = act >>= \x -> x `seq` return x
 
                      (res, handlerKilled) <- ((, False) `liftM` ioseq (handler req))
-                         `E.catch` \(e::E.SomeException) -> return (result 500 $ "Server error: " ++ show e, fromException e == Just ThreadKilled)
+                         `E.catch` \(e::E.SomeException) -> return (failResponse (show e), fromException e == Just ThreadKilled)
 
                      case mlog of
                        Nothing -> return ()
@@ -109,7 +110,7 @@
 
 -- NOTE: if someone took the inputs and never put them back, then they are responsible for the cleanup
 cleanupTempFiles :: Request -> IO ()
-cleanupTempFiles req = 
+cleanupTempFiles req =
     do mInputs <- tryTakeMVar (rqInputsBody req)
        case mInputs of
          Nothing -> return ()
diff --git a/src/Happstack/Server/Internal/Monads.hs b/src/Happstack/Server/Internal/Monads.hs
--- a/src/Happstack/Server/Internal/Monads.hs
+++ b/src/Happstack/Server/Internal/Monads.hs
@@ -385,7 +385,7 @@
     {-# INLINE (>>=) #-}
     return a = WebT $ return a
     {-# INLINE return #-}
-    fail s = outputTraceMessage s (mkFailMessage s)
+    fail s = lift (fail s)
 
 -- | 'WebMonad' provides a means to end the current computation
 -- and return a 'Response' immediately.  This provides an
@@ -527,9 +527,12 @@
 mkFailMessage :: (FilterMonad Response m, WebMonad Response m) => String -> m b
 mkFailMessage s = do
     ignoreFilters
-    let res = setHeader "Content-Type" "text/html; charset=UTF-8" $
-              resultBS 500 (LU.fromString (failHtml s))
-    finishWith $ res
+    finishWith (failResponse s)
+
+failResponse :: String -> Response
+failResponse s =
+    setHeader "Content-Type" "text/html; charset=UTF-8" $
+     resultBS 500 (LU.fromString (failHtml s))
 
 failHtml:: String->String
 failHtml errString =
diff --git a/src/Happstack/Server/SimpleHTTP.hs b/src/Happstack/Server/SimpleHTTP.hs
--- a/src/Happstack/Server/SimpleHTTP.hs
+++ b/src/Happstack/Server/SimpleHTTP.hs
@@ -26,7 +26,7 @@
 -- run a 'ServerPart'.
 --
 -- A very simple, \"Hello World!\" web app looks like:
--- 
+--
 -- > import Happstack.Server
 -- > main = simpleHTTP nullConf $ ok "Hello World!"
 --
@@ -82,7 +82,6 @@
 import Happstack.Server.Response
 import Happstack.Server.Validation
 
-
 import Control.Monad
 import Data.Maybe                                (fromMaybe)
 import qualified Data.Version                    as DV
@@ -127,7 +126,7 @@
 
 -- | A combination of 'simpleHTTP''' and 'mapServerPartT'.  See
 -- 'mapServerPartT' for a discussion of the first argument of this
--- function. 
+-- function.
 --
 -- NOTE: This function always binds to IPv4 ports until Network
 -- module is fixed to support IPv6 in a portable way. Use
@@ -138,7 +137,6 @@
 simpleHTTP' toIO conf hs =
     Listen.listen conf (\req -> runValidator (fromMaybe return (validator conf)) =<< (simpleHTTP'' (mapServerPartT toIO hs) req))
 
-
 -- | Generate a result from a 'ServerPartT' and a 'Request'. This is
 -- mainly used by CGI (and fast-cgi) wrappers.
 simpleHTTP'' :: (ToMessage b, Monad m, Functor m) => ServerPartT m b -> Request -> m Response
@@ -186,8 +184,8 @@
 -- > main = do let conf = nullConf
 -- >               addr = "127.0.0.1"
 -- >           s <- bindIPv4 addr (port conf)
--- >           simpleHTTPWithSocket s conf $ ok $ toResponse $ 
--- >             "now listening on ip addr " ++ addr ++ 
+-- >           simpleHTTPWithSocket s conf $ ok $ toResponse $
+-- >             "now listening on ip addr " ++ addr ++
 -- >             " and port " ++ show (port conf)
 --
 bindIPv4 :: String  -- ^ IP address to bind to (must be an IP address and not a host name)
@@ -204,7 +202,7 @@
       appFilterToResp (e, ff) = unFilterFun ff $ either id toResponse e
 
 notFoundHtml :: String
-notFoundHtml = 
+notFoundHtml =
     "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\" \"http://www.w3.org/TR/html4/strict.dtd\">"
     ++ "<html><head><title>Happstack "
     ++ ver ++ " File not found</title></head>"
@@ -218,7 +216,7 @@
 
 -- | Wait for a signal.
 --   On unix, a signal is sigINT or sigTERM (aka Control-C).
---  
+--
 -- On windows, the signal is entering: e <return>
 waitForTermination :: IO ()
 waitForTermination
@@ -233,7 +231,7 @@
            False -> return ()
          takeMVar mv
 #else
-         let loop 'e' = return () 
+         let loop 'e' = return ()
              loop _   = getChar >>= loop
          loop 'c'
 #endif