Any suggestions?

Chris,

The UXDesktop requires the TaskBar to perform minimize and maximize command because TaskBar is responsible to "perform" the minimize logic and "determines" the largest boundary for a maximized window, this conforms to desktop UI/UX standards.

The good news is the TaskBar property in UXDesktop is defined with ITaskBar interface type, so you can actually implement any kind of task bar user interface as long as you implement the ITaskBar interface. You can learn more about the concept here.

So in your case, yes, you can do whatever you desire for your custom task bar to do when a minimize or maximize command occur. This is done in your implementation of the ITaskBar interface, which has the following signature:

    public interface ITaskBar : IAnimationProvider
    {
        Dock DockPosition { get; set; }
        ISItemsControl Owner { get; set; }

        Point GetPositionOffset();
        Size GetSizeBoundary();
        WindowStateData GetWindowStateData(string targetState);
        bool PerformWindowOperation(IWindow window, string operation);
        bool PrepareWindowOperation(IWindow window, string operation);
    }

If your task bar doesn't implement any docking capability, you may want to always set it to Dock.Bottom (considering the most common task bar position).

The PrepareWindowOperation and PerformWindowOperation are executed consecutively when a window demands an operation in the task bar. You generally perform preparation in the PrepareWindowOperation (i.e, preparing animation and storyboard if any).

The GetPositionOffset and GetSizeBoundary tells UXDesktop the position and the size of your task bar. You need to return the correct coordinate of your task bar location, UXDesktop automatically knows what to do when performing maximize command.

Note: The interface is defined in Intersoft.Client.Framework assembly.

Hope this helps,
Jimmy

The problem is that I need to use the UXDesktopDock control or the UXDock control for the rich "Fish Eye"-like functionality.  I am successfully using the UXDesktopDock now to show an "Applications" menu at startup and to display application instances grouped together on the taskbar like Windows 7 does. 

Is there a way to override the minimize/maximize functionality of the UXDesktopDock or UXDock control so I can handle them the way I want?

You can try modifying the Maximize and Minimize behavior during WindowStateChanged event handler in the UXWindow as discussed in this thread.