Revit MEP 2010 2011 Multiple Monitors Setup : selected object moves 4 to 5 feet by itself

source: Autodesk Technical Support: customer confirmed this resolved their issue
Software:
Revit (2010 and 2011)
external monitor connected to a 64bit/32bit laptops

Issue:
when object is selected, it takes a second to actually become selected and then physically moves the object up screen.

Notes:
If you take that same file and drag it down to the actual laptop screen Revit visibly runs smoother and objects don’t jump around.

Scope:
This same issue has been confirmed on three laptops running an external monitor. Each laptop we tried it on is connected to the second monitor in a different way, one VGA, one DVI, and one HDMI. All have the same problem. Different files as well as different objects being selected have been tried on the computers also.

Proposed Workaround:
I understand that Revit is showing odd behavior when on an external monitor.
This is an issue we have seen before when running Revit in multi-monitor set ups. The reason this happens is due to Revit being in the secondary monitor. As you have seen the issue goes away when you drag Revit to the primary monitor.

PC Multi-monitor Setup:
I suggest making the external monitor the primary when running Revit.

Laptop Multi-Monitor Setup:
I suggest making the external monitor the primary when running Revit.

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Additional Notes from Autodesk:

If I understand correctly, the file runs smoother in Revit Architecture than in MEP.

Depending on the configuration of your Revit User Interface (palettes, docked or undocked, etc.), the behavior you are seeing can vary. This may explain the performance difference between Revit Architecture and Revit MEP.
Also, we have seen Revit MEP use more resources for the same files than Revit Architecture and Revit Structure.