h264 /fcp6 / quicktime mov

hi guys

i work in a fcp 6.06 qt 7.6.4 macos 10.5.8 2x2.8 ghz quad-core intel xeon 10gb ram. i received some h264 files. converted in
apple res 422, edited and the final result came with some " weard frames " in some places. in a 7 minutes material, that occurred 12 times. something like a tint filter was applied in such frames. any ideas how to avoid that problem. i noticed that occurs always in this situation : h264 into quicktime mov. i use or fcp or quicktime to do this conversion.

thanks ahead

thanks ken

i'll try that