ReSharper 5.0 Unit Test Runner Fails when Isolator Enabled

My team upgraded to VS 2010 RTM and .NET 4.0 recently. Since doing so, I have not been able to execute any tests using the R# unit test runner. I'm presented with a dialog box stating the following.

Unit Test Runner failed to load test assembly:
JetBrains.ReSharper.TaskRunnerFramework.TaskException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.

In a sample unit test project that contains a simple class and a unit test fixture and has no reference to TypeMock asseblies, if I disable TypeMock Isolator the test runs successfully. When I enable Isolator, the test fails.

I'm running:

• Windows 7 Ultimate x64 (

but failure occurs when project compiled as ANY CPU or x86)
VS 2010 Version 10.0.30319.1 RTMRel
Isolater 6.0.0.0
JetBrains ReSharper 5 C# Edition - Build 5.0.1659.36 on 2010-04-13T02:19:06
NUnit 2.5.3