NUnit can´t find selected assembly

Question

I have a few test-assemblies compiled towards .NET 3.5. When I open nunit-x86.exe however and add any of the assemblies from their build-path I get a

System.IO.FileNotFoundException...

Server stack trace: bei System.Reflection.AssemblyName.nGetFileInformation(String s) bei System.Reflection.AssemblyName.GetAssemblyName(String assemblyFile)
bei NUnit.Core.Builders.TestAssemblyBuilder.Load(String path) bei NUnit.Core.Builders.TestAssemblyBuilder.Build(String assemblyName, Boolean autoSuites) bei NUnit.Core.Builders.TestAssemblyBuilder.Build(String assemblyName, String testName, Boolean autoSuites) bei NUnit.Core.TestSuiteBuilder.Build(TestPackage package) bei NUnit.Core.SimpleTestRunner.Load(TestPackage package) bei NUnit.Core.ProxyTestRunner.Load(TestPackage package) bei NUnit.Core.ProxyTestRunner.Load(TestPackage package) bei NUnit.Core.RemoteTestRunner.Load(TestPackage package) bei System.Runtime.Remoting.Messaging.StackBuilderSink._PrivateProcessMessage(IntPtr md, Object[] args, Object server, Int32 methodPtr, Boolean fExecuteInContext, Object[]& outArgs) bei System.Runtime.Remoting.Messaging.StackBuilderSink.SyncProcessMessage(IMessage msg, Int32 methodPtr, Boolean fExecuteInContext)

Within the NUnit Project Editor I point to the test-projects config-file and select .NET-runtime 2.0.xxx as the test-project was compiled Debug/x86 with .NET-Framework 3.5.

I am even unable to load the VS-project related to that assembly which is quite annoying.

This is some piece of my test-projects config-file:

<configSections>
    <!-- Register the section handler for the log4net section -->
    <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler,log4net" />
    <sectionGroup name="NUnit">
      <!--  For .NET 2.0 Beta 2 replace the lines with the following -->
      <section name="TestCaseBuilder" type="System.Configuration.NameValueSectionHandler, System, Version=2.0.50215.44, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
      <section name="TestRunner" type="System.Configuration.NameValueSectionHandler, System, Version=2.0.50215.44, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
    </sectionGroup>
</configSections>

EDIT: also tried with nunit-console, which gave me the following:

NUnit-Console version 2.6.4.14350 Copyright (C) 2002-2012 Charlie Poole. Copyright (C) 2002-2004 James W. Newkirk, Michael C. Two, Alexei A. Vorontsov. Copyright (C) 2000-2002 Philip Craig. All Rights Reserved.

Runtime Environment - OS Version: Microsoft Windows NT 6.2.9200.0
CLR Version: 2.0.50727.8009 ( Net 3.5 )

ProcessModel: Default DomainUsage: Single Execution Runtime: net-3.5 Unhandled Exception: System.BadImageFormatException: The file or Assembly "MyTestAssembly.Test, Ver sion=6.4.3.0, Culture=neutral, PublicKeyToken=39011c0f9e8bb8bc" or one of its dependencies was not found. An attempt was made to load a program with an incorrect format. FileName: "MyTestAssembly.Test, Version=6.4.3.0, Culture=neutral, PublicKeyToken =39011c0f9e8bb8bc"

Server stack trace: bei System.Reflection.Assembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, Assembly locationHint, StackCrawlMark& stackMark, Bo olean throwOnFileNotFound, Boolean forIntrospection) bei System.Reflection.Assembly.InternalLoad(AssemblyName assemblyRef, Evidenc e assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection) bei System.Reflection.Assembly.Load(AssemblyName assemblyRef) bei NUnit.Core.Builders.TestAssemblyBuilder.Load(String path) bei NUnit.Core.Builders.TestAssemblyBuilder.Build(String assemblyName, Boolea n autoSuites) bei NUnit.Core.Builders.TestAssemblyBuilder.Build(String assemblyName, String testName, Boolean autoSuites) bei NUnit.Core.TestSuiteBuilder.BuildSingleAssembly(TestPackage package)
bei NUnit.Core.TestSuiteBuilder.Build(TestPackage package) bei NUnit.Core.SimpleTestRunner.Load(TestPackage package) bei NUnit.Core.ProxyTestRunner.Load(TestPackage package) bei NUnit.Core.ProxyTestRunner.Load(TestPackage package) bei NUnit.Core.RemoteTestRunner.Load(TestPackage package) bei System.Runtime.Remoting.Messaging.StackBuilderSink._PrivateProcessMessage (IntPtr md, Object[] args, Object server, Int32 methodPtr, Boolean fExecuteInCon text, Object[]& outArgs) bei System.Runtime.Remoting.Messaging.StackBuilderSink.SyncProcessMessage(IMe ssage msg, Int32 methodPtr, Boolean fExecuteInContext)

Exception rethrown at [0]: bei System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage re qMsg, IMessage retMsg) bei System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgD ata, Int32 type) bei NUnit.Core.TestRunner.Load(TestPackage package) bei NUnit.Util.TestDomain.Load(TestPackage package) bei NUnit.ConsoleRunner.ConsoleUi.Execute(ConsoleOptions options) bei NUnit.ConsoleRunner.Runner.Main(String[] args)