I am assuming that the DB server cannot decrypt. If the DB server has decryption permissions, and it is compromised, then there's little need in encrypting the passwords anyway as an attacker will simply decrypt them by hand. (They may not get all of them before being detected, but they'd still get some or most --- and they might look for high-value targets!)
Unlike ECB mode, you can't just encrypt the same password again and check to see if the ciphertexts are the same --- the IVs will be different (hopefully!). So, can you somehow check two ciphertexts with different IVs to see if they represent the same plaintext? Nope, probably not: if you could, then the scheme would no longer have indistinguishable encryptions under a chosen-plaintext attack [1]. Briefly, this ability to test if two ciphertexts represent the same plaintext would allow the adversary in the IND-CPA game to simply encrypt both of the plaintexts and test them against the challenge ciphertext. (See the [1] reference for more info on this.)
In fact, this is exactly the property you don't want. You don't want to be able to determine if two users have the same password. If the DB server were able to test ciphertext equality, then it could pairwise-test each pair of users (or again only hunt for high-value targets).
If you were really adamant on encrypting passwords, I'd also suggest that we'd need to pad the password out to the max password length to prevent the revelation of password length. But of course, I very strongly suggest against password encryption. Still: that's another thing to consider in this hypothetical scenario.
[1] http://en.wikipedia.org/wiki/Ciphertext_indistinguishability