How does one go about to make an Addin Module Safe? (Usable while driving)

I'm implementing the IModuleEvents interface:

Code:
namespace StreetDeck
{
    [Guid("5DC47749-697F-43B1-B458-F94B17C4DEB6")]
    [TypeLibType(4096)]
    [InterfaceType(2)]
    public interface IModuleEvents
    {
        [DispId(76)]
        bool IsSafe();
...
with this

Code:
        #region IModuleEvents Members

        public bool IsSafe()
        {
            return true;
        }
but no success...

(btw. the "module not avail..." message always puts StreetDeck info full screen mode..)