Po Regulation?

[Blubarb]

Hi guys. I hope this is the right forum to post this.

 

In December 2006 I purchased new an Omega Planet Ocean (Ref..2208.50.00  Co-Axiel.  Cal. 2500).  For the past 8 years it's been running under COSC standards in all the positions. I decided that I couldn't let it go on without a service so this year I had it serviced by a well respected and very experienced Omega watch repairer here in Australia and in another state. Now here is my problem, though I have no doubts about the quality of the service I am wondering about the regulation. I measured a +4 seconds for 24 hours when worn on the wrist for the full 24 hours which I was ok with. However, I put it in the 6 o'clock up position for 12 hours and noticed a difference of +11 which is, to me, way out. My question is, will a watch like this take awhile to settle down after a service getting the lubricant to move around?  Or is this something that needs attention immediately or should I spend more time testing different positions?  Sending it back for regulation is a costly exercise due to postage costs.