Fly-Through Mode affects all Scene Viewports

PROBLEM: With the editor configured with multiple scene viewports (ie. 4-split, top/bottom, ect.) and when using fly-through mode (RMB + W/A/S/D) each viewport is being controlled even though I focus ('f' key) within a particular viewport on a single object. Sometimes it will work correctly where it will only operated within the selected view, but as soon as I use 'Shift' key to speed up movement all viewports become active and are affected by fly-through mode; very annoying when editing (esp. if you need to see multiple perspectives on the same object, at the same time) and becomes a resource consuming monster producing visual lag within the editor if you actually need to use fly-through mode to inspect an object.

SYSTEM: OSX 10.8.5, ATI 5870 1GB, 12GB RAM

TROUBLESHOOTING: I removed all preferences/settings related to Unity from entire OSX system and deleted App folder then reinstalled Unity3D; upon success, license key was reentered and was asked if I wanted to start using Unity.

SOLUTION: None, problem still exists. Looking for suggestions/answers.

Thanks!