Go to your VI properties (Ctrl-I or File->VI Properties).
Check to see if "Maintain Porportions of window..." and/or "Scale all objects on front panel..." are checked. These will cause the front panel to adjust for different monitor resolutions.
In the same window, make sure Minimum Panel Size is not set (set to all 0's to disable) if you resize problem is you cannot make the fron panel smaller.
If you are having problems resizing when running, make sure the option "Allow user to resize window" in enabled in the Customize section of Window Appearance (Default has this options available). This option has no effect when editing the VI, though.
It may sound stupid, but make sure your window is not maximized. Under Position in Window Run-time Position, you can set the VI to maximize when it runs.
