diff --git a/hpage.cabal b/hpage.cabal
--- a/hpage.cabal
+++ b/hpage.cabal
@@ -1,5 +1,5 @@
 name: hpage
-version: 0.11.0
+version: 0.11.1
 cabal-version: >=1.6
 build-type: Custom
 license: BSD3
diff --git a/src/HPage/Control.hs b/src/HPage/Control.hs
--- a/src/HPage/Control.hs
+++ b/src/HPage/Control.hs
@@ -467,11 +467,16 @@
                                         return $ Left err
                             else if isList t
                                     then do
+                                            liftDebugIO "interpreting a list"
                                             valueRes <- getListFromExprNth i
                                             case valueRes of
-                                                Left verr -> return $ Left verr
+                                                Left verr ->
+                                                    if isNotShowable verr
+                                                        then return $ Right $ Expr{intValue = "", intType = t}
+                                                        else return $ Left verr
                                                 Right list -> return . Right $ Exprs{intValues = list, intType = t}
                                     else do
+                                            liftDebugIO "interpreting a value"
                                             valueRes <- valueOfNth i
                                             case valueRes of
                                                 Left verr ->
@@ -832,7 +837,7 @@
                                                                    lets = filter isNamedExpr $ b ++ a
                                                                    expr = letsToString lets ++ exprText item
                                                                 in do
-                                                                        liftDebugIO expr
+                                                                        liftDebugIO ("runInExprNthWithLets", expr)
                                                                         syncRun $ if "" == exprText item
                                                                                     then return ""
                                                                                     else action expr
@@ -892,14 +897,14 @@
 isList = isType isList'
 
 isChar, isList' :: Xs.Type -> Bool
-isList' (Xs.TyForall _ _ intType)          = isList' intType
-isList' (Xs.TyParen intType)               = isList' intType
-isList' (Xs.TyList intType)                = not $ isChar intType 
+isList' (Xs.TyForall _ _ inttype)          = isList' inttype
+isList' (Xs.TyParen inttype)               = isList' inttype
+isList' (Xs.TyList inttype)                = not $ isChar inttype 
 isList' (Xs.TyCon (Xs.Special Xs.ListCon)) = True
 isList' _                                  = False
 
-isChar (Xs.TyForall _ _ intType)                = isChar intType
-isChar (Xs.TyParen intType)                     = isChar intType
+isChar (Xs.TyForall _ _ inttype)                = isChar inttype
+isChar (Xs.TyParen inttype)                     = isChar inttype
 isChar (Xs.TyCon (Xs.Qual _ (Xs.Ident "Char"))) = True 
 isChar (Xs.TyCon (Xs.UnQual (Xs.Ident "Char"))) = True
 isChar _                                        = False
@@ -908,13 +913,13 @@
 isIO = isType isIO'
 
 isIO'', isIO' :: Xs.Type -> Bool
-isIO' (Xs.TyForall _ _ intType) = isIO' intType
-isIO' (Xs.TyParen intType)      = isIO' intType
-isIO' (Xs.TyApp intType _)      = isIO'' intType
+isIO' (Xs.TyForall _ _ inttype) = isIO' inttype
+isIO' (Xs.TyParen inttype)      = isIO' inttype
+isIO' (Xs.TyApp inttype _)      = isIO'' inttype
 isIO' _                         = False
 
-isIO'' (Xs.TyForall _ _ intType)              = isIO'' intType
-isIO'' (Xs.TyParen intType)                   = isIO'' intType
+isIO'' (Xs.TyForall _ _ inttype)              = isIO'' inttype
+isIO'' (Xs.TyParen inttype)                   = isIO'' inttype
 isIO'' (Xs.TyCon (Xs.Qual _ (Xs.Ident "IO"))) = True 
 isIO'' (Xs.TyCon (Xs.UnQual (Xs.Ident "IO"))) = True
 isIO'' _                                      = False
diff --git a/src/HPage/GUI/FreeTextWindow.hs b/src/HPage/GUI/FreeTextWindow.hs
--- a/src/HPage/GUI/FreeTextWindow.hs
+++ b/src/HPage/GUI/FreeTextWindow.hs
@@ -969,6 +969,7 @@
         res <- tryIn model hpacc
         case res of
             Left err ->
+                errorIO ("runHP", err) >>
                 warningDialog win "Error" err
             Right () ->
                 refreshPage model guiCtx
@@ -1028,6 +1029,7 @@
         liftTraceIO "ready"
         case res of
             Left err ->
+                errorIO ("interpret", err) >>
                 warningDialog win "Error" err
             Right interp ->
                 if HP.isIntType interp
@@ -1132,9 +1134,9 @@
         res <- HPS.runIn model $ catchError (hpacc >>= return . Right)
                                             (\ioerr -> return $ Left ioerr)
         case res of
-            Left err          -> return . Left  $ ioeGetErrorString err
-            Right (Left err)  -> return . Left  $ HP.prettyPrintError err
-            Right (Right val) -> return . Right $ val
+            Left err          -> errorIO ("IOError", ioeGetErrorString err) >> (return . Left $ ioeGetErrorString err)
+            Right (Left err)  -> errorIO ("HintError", HP.prettyPrintError err) >> (return . Left $ HP.prettyPrintError err)
+            Right (Right val) -> debugIO "Result OK" >> (return . Right $ val)
 
 -- FIND/REPLACE UTILS ----------------------------------------------------------
 data FRFlags = FRFlags {frfGoingDown :: Bool,