Firstly let me preface my question by saying that I have been searching on the forums and on google for quite a while, and as yet haven't found an answer to my problem. So if my question has been answered before (amongst the 3000 odd pages of topics), I'm sorry to bring it up again, and would you be so kind as to point me the right direction? Thanks!
Anyway, on with the problem. So far this has happened to me in 4 different places in the world - first on Geneva approach in PMDG 737 (on a previous install of FSX...now it doesn't happen there for some reason), Zurich (PMDG 737), Florence LIRQ (Carenado cessna - can't remember which) and New York Kennedy (FSlabs concorde), with KJFK being the most recent.
What happens is that approaching ILS capture, and from then until shutdown, FSX begins to freeze for 5 seconds or so, then unfreeze for 5 seconds. This repeats over and over again, with the freezes getting longer as I approach the airport. Obviously when it happens now I simply switch off, as I know what will happen. But on a couple of occasions I've let the plane autoland to see if it disappears once at the airport, or below a certain speed, but it doesn't seem to do so.
At first I thought that it must have something to do with being close to mountains, until it happened in New York (incidentally, it happens at La Guardia as well, so it must be something other than airport specific scenery).
In Italy it didn't happen at nearby Pisa.
I have landed in Innsbruck, Sion, Salzburg, and many other places in the mountains, so it can't be that!
If I load up FSX starting at one of these airports it happens as well (not only approaching ILS).
It's definitely not linked to graphic settings - the disruption to framerate when I have stuff turned up to high is very distinct to this.
Most of the places I land are totally fine, but it's just these few (and I assume some others that I've never landed at) that have the problems.
So, in advance many thanks. I dearly hope that someone has seen/heard about this problem, as I don't want to live my life not flying to New York!!!!