Thud_Driver - sorry, you need to read some of the previous posts on the forum where the topic was thrashed to oblivion. For a down force at the tail the CG of the airplane needs to be ahead of the wing CP but that would be a CG of 0 to 25 percent. On an airplane like the Cap which is primarily an aerobatic machine the wing CP which is at 25 percent is ahead of the CG which is probably 30 percent. The CG is ahead of the airplane NP however for stability. If you work out the force vectors and moments that gives you an up force on the stab.

If for some reason the stab enountered a change in downwash at a very narrow range of angle of attacks such that the up lift on the tail was reduced then it could indeed cause a slight pitch up.

If I remember correctly the lift on the tail is proportional to (1 - de/da) where de/da is the change in downwash with reapect to angle of attack. Since there is a variation in downwash with angle of attack and a variation in horizontal tail position with respect to the airplane pitch angle it is entirely possible that this is the problem. The Cap does have the horizontal tail somewhat high compared to most aerobatic machines.

As such, there isn't much you can do about it. Just be prepared to feed in a little forward stick at the appropriate time.