JSONRPC response different to geth

[gavofyork]

$ curl -X POST --data '{"id":10,"jsonrpc":"2.0","method":"eth_call","params":[{"from":"0xb5f7502a2807cb23615c7456055e1d65b2508625","to":"0x2828a20e3ce771571177928077bfbbcdd16df764","data":"0x80b5e7bd00000000000000000000000000000000000000000000000000000000000f69b5","gas":"0x2fd618"}]}' http://localhost:8545

geth gives

{"id":10,"jsonrpc":"2.0","result":"0x0000000000000000000000000000000000000000000000000000000000000778"}

parity gives

{"jsonrpc":"2.0","error":{"code":-32602,"message":"Invalid params","data":null},"id":10}

[gavofyork]

addressed in #828 and #829