[randantor]

It's unlikely that the field is affecting your timing. Whether on the field or in testing, timers in your robot code should act the same; there's no difference in what processing happens where. Instead I would look at your cRIO CPU usage. If you're consistently maxing the robot CPU, it will throw off any timing you have in your code because the cRIO is unable to keep up with time constraints. If enabling cheesyvision makes your timing worse, it sounds to me like whatever code you have is running at 100% CPU, and adding the cheesyvision receiver is just woresning it by increasing the CPU load.

Watch your CPU usage while running autonomous, and if the CPU is running at 100% check for code errors showing up on the diagnostics tab of the driver station, and if there are no errors causing a CPU spike consider slowing down loops that you have running, and make sure that no loops are running without a delay.