I too suffered the same problem, sounds like a few others have as well. In tour 2 i had a half respectable k/d ratio of 1.5:1 and it degenerated to about 0.8:1 in tour 3 and my gunnery percentage dropped off too. I put it down to:
1. Version 1.2 and above decreased FPS due to more details - got down to 13 FPS at times when i had a gun solution

2. I re-installed totally and lost my gunsight, and JS setup.
3. My crappy monitor died so i had to borrow a crud 14"
4. Bad luck
5. constantly changing my ride (I was a spit dweeb all the time and decided to experiment)
6. Getting too confident
how much of this is truly a factor or just an excuse im not sure, but i went about solving all of them:
1. bought a K7 650
2. tweaked the default JS setup
3. bought a new 17" monitor
4. Got on with it.
5. Settled on the p-51 as my default ride.
6. stopped being a over-confident pilot.
Now i can use those excuses. I also changed my gunsight to AKWabbits historical P-51 red diamonds sight.
I think there has been an improvement.
Not sure if this helps or just annoys you but you aint alone in the 'loser streak'.
Spat.
[This message has been edited by Spatula (edited 05-15-2000).]