There is one ugly solution, depending on your number of entries... You go into the contact that has a bday entered. You select "none" and save it, then go back in and enter "date" again, then save - this works but it is most frustrating to do over 400+ contacts one at a time...
These bugs are alfa-stage, would imagine they would have been resolved in version 3.x.x.xxx or something. Lets hope 6.x.x.xxx is beyond such teething bugs
I actually have my contact birthdays entered differently, but I still have the same problem. I enter the contact birthdays into Outlook based on date, and not based on contact. So, I go directly to a date with a birthday and add an item for the contact's birthday.
However, while appearing in my Outlook calendar, it doesn't carry over on to my BB.