Excel autocomplete formula doesn't read

[Qchristensen]

When typing a formula in Excel, a drop down list appears with auto complete options for what has been typed so far. If I type =cou for instance, a list will appear with COUNT, COUNTA, COUNTBLANK etc. When you arrow through the list, a tooltip appears explaining each function ("Counts the number of cells in a range that contain numbers" for COUNT).

Pressing TAB inserts the currently selected function from the list ready to add arguments. Nothing is read when moving through the list or when TAB is pressed and the function is added to the current cell (the dropdown appears for nested functions as well).