Creaking headset........help please!!!

My problem is I have runout of ideas to stop my headset from creaking. Some of the history is:

1. Original headset was a Campag record which was in the bike for 7 years with no problems until this started to creak. This was due to the bearings going from water leaking into headset. The bearing races were pitting therefore decided to install a new headset. The headset is the old style threaded.
2. The local bike shop installed a FSA headset, this would not stay tighten. By the end of a Sunday ride it was loose and needed to be tighten. This resuled in three trips to the LBS with no success. A decision was made to install another headset from Shimano this time.
3. The Shimano headset does not come loose but it creaks out on the road. Back to the LBS and a different type of bearing installed. This lasted for 3 hours on the road before the creaking started again. I have been back to LBS with no further success.

Any ideas what could be causing this?

 

Does the noise happen when you are pulling on the bars in any way? If you are using a quill stem it might be the stem creaking in the steering tube. I had that problem on an old threaded stem bike when I switched quill stems. I fixed it with a shim made from a "Red Bull" Al can. That stopped the creaking forever. I still have the bike and it doesn't creak even on mt climbs.