60D: SOLVED something wrong with the live view

[wzh19940105]

i've successfully installed ML 2.3 in my 60D (fir 1.1.1), but when i turned the live view on, i found that the image on LCD was very unfluent. Just like i was seeing a PPT.
i've searched but i found no bugs similar to mine.
with this kind of live view i cannot use almost all functions of ML.
So I NEED HELP!!
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When i turned off the FPSoverride, everything worked fine.