Code:
09:59:08 9 Script.processMultiSig: Non-canonical public key: Key 0000400800150016002300420000400800150016002300420000400800150016002300420000400800150016002300420000400800150016002300420000000000
09:59:08 9 Script.processMultiSig: Non-canonical public key: Key 0000400800150016002300420000400800150016002300420000400800150016002300420000400800150016002300420000400800150016002300420000000000
09:59:32 9 BlockStoreLdb.setChainHead: Block added to block chain at height 291820
000000000000000056103025e0b77f2fcc75d85abd7d179bd7cd2fc01d5f85a2
09:59:32 9 BlockStoreLdb.deleteSpentTxOutputs: Deleting spent transaction outputs
09:59:33 9 BlockStoreLdb.deleteSpentTxOutputs: 4,074 spent transaction outputs deleted
10:01:23 9 Script.processMultiSig: Non-canonical public key: Key 0000400800150016002300420000400800150016002300420000400800150016002300420000400800150016002300420000400800150016002300420000000000
10:01:23 9 Script.processMultiSig: Non-canonical public key: Key 0000400800150016002300420000400800150016002300420000400800150016002300420000400800150016002300420000400800150016002300420000000000
10:01:25 9 BlockStoreLdb.setChainHead: Block added to block chain at height 291827
0000000000000000cf0fbb1878c2a4a3b4f41cadaaf63dce470f927b566f0e4e
10:01:25 9 BlockStoreLdb.deleteSpentTxOutputs: Deleting spent transaction outputs
10:01:26 9 BlockStoreLdb.deleteSpentTxOutputs: 0 spent transaction outputs deleted
09:59:08 9 Script.processMultiSig: Non-canonical public key: Key 0000400800150016002300420000400800150016002300420000400800150016002300420000400800150016002300420000400800150016002300420000000000
09:59:32 9 BlockStoreLdb.setChainHead: Block added to block chain at height 291820
000000000000000056103025e0b77f2fcc75d85abd7d179bd7cd2fc01d5f85a2
09:59:32 9 BlockStoreLdb.deleteSpentTxOutputs: Deleting spent transaction outputs
09:59:33 9 BlockStoreLdb.deleteSpentTxOutputs: 4,074 spent transaction outputs deleted
10:01:23 9 Script.processMultiSig: Non-canonical public key: Key 0000400800150016002300420000400800150016002300420000400800150016002300420000400800150016002300420000400800150016002300420000000000
10:01:23 9 Script.processMultiSig: Non-canonical public key: Key 0000400800150016002300420000400800150016002300420000400800150016002300420000400800150016002300420000400800150016002300420000000000
10:01:25 9 BlockStoreLdb.setChainHead: Block added to block chain at height 291827
0000000000000000cf0fbb1878c2a4a3b4f41cadaaf63dce470f927b566f0e4e
10:01:25 9 BlockStoreLdb.deleteSpentTxOutputs: Deleting spent transaction outputs
10:01:26 9 BlockStoreLdb.deleteSpentTxOutputs: 0 spent transaction outputs deleted
I'm rejecting non-canonical public keys since that is another source of transaction malleability. Interestingly enough, this doesn't cause the signature verification to fail since the remaining public keys are sufficient to sign the transaction.
I don't know what software package is creating the public key, but this might become a problem down the road if the reference client decides to enforce canonical keys.