Currently, I can't use Edit > Undo for typing text in Photoshop like typing in a Word document. The only undo option that I can do is if I switch back to the Move Tool. The problem is if I use an undo, it undoes every single text change that I did while the Text Tool was selected. For example, I'm going through and adjusting the tracking on several lines of text. I'll type the number in the tracking field. When I go to click Enter, occasionally I'll miss the key and hit the button next to it. That erases the entire line with the number 3. Unfortunately, there doesn't seem to be a way for me to undo that without undoing every action that I've done since activating the Text tool.