Azure diagnostics - Event Source is always disabled

Question

I am trying to log the ETW events by enabling Azure Diagnostics in my cloud service. After deployment, if I check in the Diagnostics Configuration dialog, ETW logs seems to enabled. Also, all the WAD* tables get created but my custom ETW tables specified in diagnostics.wadcgfx file are not created at all. Here is the logging code -

public sealed class VstsEventSourceWriter : EventSource
{
    public void LogException(int eventId, string ErrorMessage, string ExceptionType, string ExceptionMessage, string Stacktrace)
    {
        if (IsEnabled())
        {
            WriteEvent(eventId, ErrorMessage, ExceptionType, ExceptionMessage, Stacktrace);
        }
    }
}

code in diagnostics.wadcfgx -

    <EtwProviders>
      <EtwEventSourceProviderConfiguration provider="VstsEventSourceWriter" scheduledTransferPeriod="PT5M">
        <Event id="1" eventDestination="Table1" />
        <Event id="2" eventDestination="Table2" />
        <Event id="3" eventDestination="Table3" />
        <DefaultEvents eventDestination="DefaultTable" />
      </EtwEventSourceProviderConfiguration>
    </EtwProviders>

If I debug in the service, isEnabled() is always False. So WriteEvent is never gets called. I am using Azure 2.9 SDK with .NET framework 4.5. What should I check for this logging to work? I have enabled the Diagnostics for Worker Role from its Properties in VS and specified the Storage Account details to store the diagnostics results.