Dunno. Might explain why it seemed to be flying perfectly fine with a prop that wasn't rotating.

Anyway I went back the other night to IL2 after a week or two away from it, played a 633 Squadron campaign Mosquito mission (twice because it crashed to desktop on me, think it was a memory issue as I use the SAS Mod selector and had the memory usage set to 1024mb which that mission possibly didn't like because it worked fine 2nd time with memory on 512mb), and also a P51 Mustang mission from the Y29 Legend campaign, the 1st one, and I flew both fine, and landed both OK (the odd bounce here and there not withstanding), although I failed to shoot down 3 slow German planes (can't recall what they are, they look like boat-planes) that are spawned on the return leg of that 633 Squadron mission (seems my aim was off/I didn't cause enough damage and I ran out of ammo!!).

I'm wondering if some of the problems I have with regards to landing are related to trimming for level flight, because the other night when I did those two missions I trimmed both planes on approach with a slight lift.

I quite often don't do that, thus the plane I'm flying is usually trimmed for level flight at cruising speed, or as good as I can get it.

Or maybe I just had a good night when it comes to successful missions (with 2 relatively easy missions) and landings...

Trimming for approach and landing helps IHMO, and depending on which plane you fly and how your stick is set up may even be crucial. If your stick is set up with decreasing sensitivity the more you are from stick center, then trimming your plane for landing can shift your needed stick movement for a successful flare from the outer less sensitive zone of your stick to the inner zone. I personally trim my planes heavily into nose up before - or more while landing, as speed bleeds off.