I am attempting to fix this issue myself right now. Basically I have 3 calendars on my Blackberry device and 5 calendars on my Mac. What I find works best for me, even though this technique still has some short comings.
1. I pick my "work" calendar first and I sync only that calendar to my BlackBerry under the corresponding email.
2. After I check my "play and birthdays" calendar on my desktop manager and change over my default email on my Blackberry so all of my "play and birthday" appointments are added under the correct corresponding email on my blackberry.
3. Then I add my "home" calendar, switch over the default email again and sync one last time.
Basically it's a patience thing and you have to do it one by one. I always start with the calendar that has the most appointments, check that first, then go to the one with the second most, etc.... Just remember do not uncheck the calendars that have already been synced.
I will admit I've had issues with some birthdays, you can read about that issue here
http://forums.crackberry.com/showthr...15#post6749315. We're still waiting on a solution though. Let me know how it works for you and if you find out about anything better for either issue!