It's easy to cooperate with people who are awake and working at the same time as you. Managing projects up and down the US east coast was easy from Toronto.
If you have people in San Francisco that start 3 hours later, you have to intentionally organize for that time difference. Some people here worked late hours (including at least one night-owl friend who liked to come in at noon), while others cursed the absence of their colleagues. Still other gloried in the absence, and said things like "I get three uninterrupted hours of work!"
If QA was in Ireland (or India, or both) then people learned to hand off discrete chunks, and get the results in the morning. With people across either the Atlantic or Pacific, you get one meeting a day, so make the best of it!
One group did time-critical diagnoses, and had three shifts running: Singapore, Grenoble and San Francisco. They passed the same bug around the world, working continually on it until they got done.
Working in multiple timezones can work well, but only if you plan for it.
If you don't plan for it, you'd better keep your business in the zone you're in.