I've also tried this, but still no luck:

public class RegisterEvents : IApplicationEventHandler

{

    public void OnApplicationInitialized(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext)

    {

        LogHelper.Debug(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType,

            "#debug1: OnApplicationInitialized");

    }

To be clear I'm looking in the umbracoLog table for results

Finally got this working. Looking in the wrong place for the log was one issue :p

For the record: this code works

public class RegisterEvents : ApplicationEventHandler
{
    protected override void ApplicationStarted(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext)
    {
        //#debug - this logs to /App_Data/Logs/UmbracoTraceLog.txt
        //LogHelper.Error(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType,
        //    "#debug1: ApplicationStarted", new Exception("#ex1"));

        ContentService.Saved += ContentSaved;
    }

    private void ContentSaved(IContentService sender, 
        Umbraco.Core.Events.SaveEventArgs<Umbraco.Core.Models.IContent> e)
    {
        //#debug
        //LogHelper.Error(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType,
        //    "#debug11: ContentSaved", new Exception("#ex11"));

        //calculate and save vat
        int contentId = e.SavedEntities.First().Id;
        //etc
    }
}

Thanks @Mark, I've seen many ways of doing this and this one is the first one that's worked for me, so thanks for sharing :)

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