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I really thought a Mac person would have helped you by now. But that's not the case, so three things first.
1. Way back when, I had some trouble with the Mouse sync tool, so I haven't used it for ages and can't say for sure.
2. I don't have a Mac, so can't say for sure.
3. I like to help wherever I can. That I can say for sure.
In my Windwoes guest there is an icon in the system tray(beside the clock) for Parallels tools. When I open that, I see that every other tool has an "enable" check box. It should be just a matter of unchecking that box.
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