I suspect that this has nothing to do with NX, but check this out.
Go to the Windows 'Start' menu and select the 'Control Panel' item and then the 'Mouse' item and on the tab titled 'Pointer Options', check the 'Snap To' option. If it's toggled ON, toggle it OFF, hit OK and see if this solves your problem.
John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Digital Factory
Cypress, CA Siemens PLM: UG/NX Museum:
To an Engineer, the glass is twice as big as it needs to be.