Recurrent Job runs 7 times on trigger

My recurring job bills my clients on a set date using cronexpr. What happens is that it triggers and bills the client account 7 times on each occasion. I do not know what is happening. I have this pseudo code below

  public static void AutomaticPayDo(int id)
   var auto = db.AutomaticPayments.Where(i => i.DDPayId == id).ToList();
    for (var i = 0; i < auto.Count; i++)
      create invoices
   process payment  - with total payment required value
    if successful
    update invoice as paid
     send email

The cron reads like this in dashboard
At 06:00 PM, on day 24 of the month
Dashboard reads 40 workers
Server is a Quad Core

I’m having this exact problem in 1.7.0 (and had it in the versions of 1.6.x previously). Sorry to see that it didn’t receive a reply.

It may or may not be related but the HTML on every admin page is repeated twice - the whole HTML of each admin page is literally repeated when I view source on it. This includes the job page where I am checking the box and clicking “trigger now”. This was also happening on the earlier versions.