import issue with IronPython [SOLVED]

I'm trying to import the os module with this little script:

import sys
sys.path.append("c:\python25\lib")
import os

print os.getcwd()

print " Press Enter to quit . . . "
raw_input()

If I run it with ipy.exe, it works.

If I run it through SharpDevelop, there's an exception:

IronPython.Runtime.Exceptions.ImportException: No module named errno
   at DLRCachedCode.Program
   at Microsoft.Scripting.ScriptCode.InvokeTarget
   at Microsoft.Scripting.ScriptCode.Run
   at IronPython.Runtime.PythonContext.CreateModule
   at IronPython.Runtime.ModuleLoader.load_module
   at Microsoft.Scripting.Actions.MatchCaller.Call3
   at Microsoft.Scripting.Actions.CallSite<Microsoft.Func<Microsoft.Scripting.Actions.CallSite,Microsoft.Scripting.Runtime.CodeContext,System.Object,System.Object[,System.Object>>.UpdateAndExecute
   at Microsoft.Scripting.Actions.UpdateDelegates.Update3
   at IronPython.Runtime.PythonContext.Call
   at IronPython.Runtime.Importer.FindAndLoadModuleFromImporter
   at IronPython.Runtime.Importer.TryLoadMetaPathModule
   at IronPython.Runtime.Importer.ImportTopAbsolute
   at IronPython.Runtime.Importer.ImportModule
   at IronPython.Runtime.Builtin.__import__
   at Microsoft.Scripting.Actions.MatchCaller.Call7
   at Microsoft.Scripting.Actions.CallSite<Microsoft.Func<Microsoft.Scripting.Actions.CallSite,Microsoft.Scripting.Runtime.CodeContext,System.Object,System.String,Microsoft.Scripting.IAttributesCollection,Microsoft.Scripting.IAttributesCollection,IronPython.Runtime.PythonTuple,System.Int32,System.Object>>.UpdateAndExecute
   at Microsoft.Scripting.Actions.UpdateDelegates.Update7
   at IronPython.Runtime.Importer.Import
   at IronPython.Runtime.Operations.PythonOps.InitializeModule
   at PythonMain.Main