I don't have BiaB in front of me.
Are they Real Drums?
Do they seem to be exactly out of sync by two measures?
In the "old days" Real Instruments sometimes would be off by the length of the click-intro.
This was fixed with a patch upgrade.
Do you have the latest patch for your version installed?

A quick fix mighty be to try unchecking the click-intro or just slide the drum track into place in your sequencer.