Enable Prevent access to drives from My Computer but allow access to specfic folders

Hi,

I would like to use the Prevent access to drives from My Computer policy to stop users from browsing the local c drive but enabling this policy stops users being able to access the My Sharepoint Sites from within Office 2007 applications. Is there anyway to stop users browsing the c drive but still allow access to My Sharepoint Sites which is stored in the users profile on the c drive