Somebody already had the problem but their was with a different version and seemed to involve NCover.
I am using version v5.4.5.0. I have both the 32-bit and 64-bit versions installed on my box, because different launching programs seem to need different versions. When running from inside VisualStudio through ReSharper everything works fine, however when running from Nant I get:
[gallio] System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
[gallio] at System.ServiceModel.Description.ConfigLoader.CheckAccess(IConfigurationContextProviderInternal element)
[gallio] at System.ServiceModel.Description.ConfigLoader.LookupService(String serviceConfigurationName)
[gallio] at System.ServiceModel.ServiceHostBase.LoadConfigurationSectionInternal(ConfigLoader configLoader, ServiceDescription description, String configurationName)
[gallio] at System.ServiceModel.ServiceHostBase.ApplyConfiguration()
[gallio] at System.ServiceModel.ServiceHostBase.InitializeDescription(UriSchemeKeyedCollection baseAddresses)
[gallio] at System.ServiceModel.ServiceHost..ctor(Object singletonInstance, Uri[] baseAddresses)
[gallio] at ControllerTest.ControllerServiceTest.SetUp() in d:ControllerTestControllerServiceTest.cs:line 56