I just got really irritated with the menu or quick menu being activated when I pressed the directional buttons.
If you do try it, you will see that the part covering the buttons is soft, but there is a tougher plastic border surrounding that. You will have to cut as far as the plastic border otherwise you'll have trouble pressing the softkeys. I suggest cutting from the back of the cover (ie the part that makes contact with the phone, not the part you touch) and then trimming as necessary from the front.
Thanks for the tip. I'll do it tonight. I don't have the front cover with me at the moment. I only use the back part.