Tim,
another thing that hasnt been mentioned, based on personal experience ( ask Randy Powell about my streak of contest crashes two year ago!) I wonder if perhaps your airplane is letting you down. If it is not trimmed to respond appropriatly,, tail heavy, nose heavy, or power delivery is not up to snuff, then the airplane could be exasperating your problems. If its tail heavy it may want to tend towards tightening up yoru loops, if nose heavy, it will tend towards opening yoru loops. If power delivery is not appropriate, it could be breaking at the wrong times accelerating the plane at the ground, thus opening up your loop, or ... * on and on**
serious, I would look at what your flying and perhaps changes need to be made there which will help with the problem,,
Of course inputing the proper control before you smack the ground helps too LOL,,
see you in Eugene