Nick - If you need to retain the 2009 Toolbox to be used with SolidWorks 2009, then I would make a copy of that Toolbox for use with 2010. If you would look at my list of Toolbox folders, you would see one for 2008, 2009 and 2010 so that I use any version of SolidWorks without worry.
If you don't know where your Toolbox folder is, go to your Tools > Options > Hole Wizard/Toolbox to get the root folder. Copy that folder and then point 2010 to that new folder.
Best of luck,
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