Multithreading with ArcObjects

I am getting some weird errors while trying to implement multithreading with ArcObjects. I am trying following things on per thread basis:

1) Open SDE Workspace
2) Open Feature class
3) Perform Icursor

Eventually, It fails with some errors like: "Memory could not be read or write" or "AccessViolationException".
Looks like there are some memory leaks (though I don't know exactly where).

For more details please refer to the code below:

foreach (string featureClassName in settings.FeatureClassNames)  
{  
            Thread thread = new Thread(new ParameterizedThreadStart(ReadFeatureClass));  

            thread.ApartmentState = ApartmentState.STA;  
            object[] parameters = CreateParameters(featureClassName);  
            thread.Start(parameters);  
}  
    private void ReadFeatureClass(object parameters)  
    {  
        Settings settings;  
        string featureClassName;  
        ExtractParameters(parameters as object[], out settings, out featureClassName); 
        IFeatureWorkspace featureWorkspace = OpenFeatureWorkspace(settings); 

        ITable featureClass = featureWorkspace.OpenTable(featureClassName);  
        Marshal.ReleaseComObject(featureClass);  
        Marshal.ReleaseComObject(featureWorkspace);          
      }    

    private IFeatureWorkspace OpenFeatureWorkspace(Settings settings)  
    {  
        IWorkspaceFactory workspaceFactory = new SdeWorkspaceFactory();  
        IPropertySet connectionProperties = new PropertySet();  
        connectionProperties.SetProperty("SERVER", settings.Server);  

        connectionProperties.SetProperty("INSTANCE", settings.Instance);  
        connectionProperties.SetProperty("USER", settings.User);  
        connectionProperties.SetProperty("PASSWORD", settings.Password);  
        connectionProperties.SetProperty("VERSION", settings.Version);  

        IFeatureWorkspace featureWorkspace = workspaceFactory.Open(connectionProperties, 0) as IFeatureWorkspace;  
        return featureWorkspace;  
    }