Thanks, Admin Person, this solved my problem too.
Removing the Mapswitcher also worked perfectly for three of my Flex viewer implementations. Thanks @Admin Person!
As a side note, since this means you'll need to keep the Layer List Widget open to toggle layers, it helps to drop an x and y screen coordinate to place the Layer List widget in a desirable location upon loading. If not, it obscures a bit of the navigation tool by default. I used x="25" and y="300" and it worked great.