After a few months off of x-plane Ive now updated to 10.5 and wanted to get back into the 737 Classic. In the beginning I had unacceptable stutters every 2-3 seconds, but those were finally solved with the adaptive half refresh rate trick. Unfortunately the stutter now is back, but where it used to be consistently every 2-3 seconds on the ground and in the air they are now farther apart, maybe every 5-7 seconds.They are not very evident on the ground while taxing or during take off and landing, but are very evident in the air at lower altitudes. I also checked some of my other payware such as the 767 and MD80 and they still fly very smooth, no stutters. Its a beautiful aircraft that I want to be my 'go to' commercial airliner, but I'm obsessive about consistent stutters and hiccups, so with the other very good big jets available, it will go back into the hangar. Is there any more work being done to find and correct the root cause? Thanks