I think a problem you might be having is in this section of code:
Once you set nSyncedMotors to synchAC and nSyncedTurnRatio to 100, motors A and C will stay synched together doing a turn for the rest of the program. If you want to make them go straight, you need to set nSyncedTurnRatio to 0. And, if you don't want them synced anymore, you can set nSyncedMotors to synchNone.
P.S. Helpful hint: If you put [_CODE] [_/CODE] tags (without the underscores) around your code in your post, it will preserve the formatting and make it much easier to read!
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