The following text was removed from the KeyPairGenerator class description:

"If the algorithm is the DSA algorithm, and the keysize (modulus size) is 512, 768, 1024, or 2048, then the Sun provider uses a set of precomputed values for the p, q, and g parameters. If the modulus size is not one of the above values, the Sun provider creates a new set of parameters."

Which should be in the JDK Providers Guide instead.