This may be nothing to do with the OC. Q6600 overclocked to 3.0 GHz (may go higher later), cooled with Thermalright Ultra-120. Overclocked DDR3-1600 as well, system seems to run stable other than FSX. I have always had "stutters" of some type, but now I get actual pauses where the sound disappears and the sim stops- almost like the entire PC is pausing, but I only see this in FSX. It's been a while since I over-clocked but this "pausing" is more recent, so may not be related.Thanks for any suggestions, Bruce.

Well first thing to do is save your current overclock and run the computer in default and see if it changes anything, then take it from there.

Agree with first reply but please post your system specs if you'd like better educated answers. Other hardware affected by the overclock could be affecting your FSX. Oh, BTW, did you delete your FSX.CFG after overclocking? You may need to let FSX build a new one.I run my Q6600 at 3.30 GHz, and its been fairly stable with the odd crash now and then (I think it's time for a rebuild, but only when I get my full release copy of Win7 :( ).When I started learning serious overclocking, I learned that the biggest stabiliser of my overclock was to add a little extra voltage to the memory bus and the FSB (in the BIOS). Trust me, you will find many more ways how not to overclock before you finally start getting it right and hitting the high notes.Good luck and smooth skies.

Agree with first reply but please post your system specs if you'd like better educated answers. Other hardware affected by the overclock could be affecting your FSX. Oh, BTW, did you delete your FSX.CFG after overclocking? You may need to let FSX build a new one.I run my Q6600 at 3.30 GHz, and its been fairly stable with the odd crash now and then (I think it's time for a rebuild, but only when I get my full release copy of Win7 :( ).When I started learning serious overclocking, I learned that the biggest stabiliser of my overclock was to add a little extra voltage to the memory bus and the FSB (in the BIOS). Trust me, you will find many more ways how not to overclock before you finally start getting it right and hitting the high notes.Good luck and smooth skies.

Thanks guys,I did finally un-install a spyware app that I had and it made a lot of difference, however I'm also thinking that replacing my somewhat dated Q6600 / GA-X38T-DQ6 system with a Core i7 might be a good idea (I asked in a separate thread here what a good mobo recommndation might be).Thanks again for the replies,Bruce.