somdhunter,

are you using a peepsight?

make sure your not tilting your head downward to look through your peep if you are raise your peep sight up and your sight bracket will follow that lead...or if you arent using a peep the same applys...keep your head up...

***anchor point may also be the culprit, if your anchorpoint is high...your sights will sit low in the bracket. if you lower your anchorpoint it could remedy the problem as well.