I just upgraded to OS X Yosemite and this new "feature" appeared. I often have several email addresses that contain the same set of characters. I just type the first few characters and then select the appropriate email address from the dropdown menu that appears. But if I hit return afterwards to enter another email address, the first address gets switched back automatically to the first one that appeared in the dropdown menu. The more characters I type, the more accurate it is, but it totally defeats the purpose of autofill if I have to type the entire email address! Anyone else having this problem? And can you guys please fix it? If you select something from the dropdown menu, it should stay selected.

Thanks!