Show Base Page on Top

You can arrange  the z-order on the display page layers and individual controls on the layers, but the base page will always be behind all other layers. 

I've found IQANdesign doesn't always render the base page z-order behind all other layers, but IQANsimulate does.  Assuming that means the MD4 will render correctly too.

While editing in IQANdesign you can switch off visibility of a layer or individual display page control with the "eye" symbol. 

This only affects IQANdesign, not the simulator or the real MD4.  

As the base page layers are not shown in the list of layers on the regular display pages, it could be hard to spot this, you'd need to check visibility on the base page itself.