There are two thumb wheels below the streeging wheel. One (the upper) is the strg dual rate. This may be part of the prob - the setting for this is on the display screen - top right corner (D/R : 100), it should be 100.

If its not end point adj (epa) either or in combo, try a model reset from the menu. This radio has 3 levels of menus and something can be set in a higher menu that you might not see because of the way menus are laid out. Model reset sets everything back to defaults so you can adj from the starting point.

You def need teh manual with this one....