The BAB of a dragon is equal to its HD
The "Base attack" listed for dragons does not included their strength. The Grapple listed includes BAB,Str and Size.
However, the "Attack" column listed does include the following: BAB, Str, Size. The reason for this is that dragons (unlike other monsters) do not have listed attacks. The have an "Attack" which suffers a penalty for certain iterative attacks.
Thats all corrects as per SRD, I believe.
Majere