I showed someone a demo of my line of business (add customer, add invoice etc) type app last night, and they provided me some feedback. Their biggest point of concern was how to navigate to the next field/textbox. They tried enter and arrow down/up. Neither worked. I told her she had to press tab and shift-tab.
She'd never heard of tab. This came as a big surprise to me.
She was very strong in her criticism, insisting that enter or down arrow are the 'standard'. It's easy enough to code, but it will introduce some inconsistencies, like 'when keyboard focus is on a dropdownlist, the down arrow will change the selected item, rather than move to the next field'.
In your experience is enter and/or arrows a common way to navigate between fields? What, if anything, is the standard behavior?