Can someone enlighten me on why the following transaction is being rejected by Bitcoind 0.9.1 with error code -22 on Mainnet.

Debug.log shows the following:

Here is the decoded transaction:

{
   "lock_time":0,
   "inputs":[
      {
         "prev_out":{
            "index":0,
            "hash":"b8918ff0fe2171584b771acb07dc120c7e515e3d3a0cd7846e924bf8c1a89455"
         },
         "script":"48304502202f534407f6dee4d8932ec22491cbc15a2d31af2bade4e8d417e4b1955de57f5902210086e2f0210c16ffff9b85074429b1b1c2f32e19509d7ed19f7804ab7212bd183a012102add59262e234c0045d1f6a3d40a144b47ea0b4214916f55fb6029a079cc0b3cb"
      }
   ],
   "vout_sz":3,
   "hash":"44130e812fa15f411c6accb739082eb81ecf074470cefb8e617ecf105690f6e1",
   "vin_sz":1,
   "out":[
      {
         "address":"12QkihKUyE1hAkv7wmaMj6V3QiN8FfMvpv",
         "script_string":"OP_DUP OP_HASH160 0f763005e063382f8f4138f75cdc64d14f8ec16f OP_EQUALVERIFY OP_CHECKSIG",
         "value":600,
         "script":"76a9140f763005e063382f8f4138f75cdc64d14f8ec16f88ac"
      },
      {
         "script_string":"OP_RETURN 4f41010001 753d",
         "value":0,
         "script":"6a054f4101000102753d"
      },
      {
         "address":"12QkihKUyE1hAkv7wmaMj6V3QiN8FfMvpv",
         "script_string":"OP_DUP OP_HASH160 0f763005e063382f8f4138f75cdc64d14f8ec16f OP_EQUALVERIFY OP_CHECKSIG",
         "value":34400,
         "script":"76a9140f763005e063382f8f4138f75cdc64d14f8ec16f88ac"
      }
   ],
   "size":245,
   "version":1
}

Outputs are above dust, inputs are not spent. OP_RETURN is supposed to be standard in 0.9.1 and the data is well below 40 bytes, so why is this being rejected?

Thanks,

Flavien