I am running Windows 7 Ultimate (64bit). I have a Wacom Bamboo model MTE-450 (MTE-450/K(A)). I didn't however, install any software for this device, not even the Windows Update (Wacom Technology - Input - Wacom Mouse Monitor) date January 2010 published 2/25/2010. The device seems to work fine on my computer, without any issues.
Perhaps you have a software conflict as you seem to suspect. Is there something in the Wacom software, that you need that is not present in the Win7 native driver support? If not try unplugging the device, and uninstalling the proprietary software and any related device drivers that were part of the package, and reboot, plug the device back in and see if the native driver support resolves your issue.