It's been over 16 hours now, no signs of the transaction on blockchain.info or my local client (not even unconfirmed) so I think I can safely say it wasn't a double spend.

Just tried pushing again via bitcoin client and it gave me the same error: "TX rejected (code -22)"

I would be curious to see the full list of error codes (does anybody have this? It would be extremely helpful), once again I looked hard for this on the internet but was unable to figure out what this error means.

Also, I just tried an empty "signrawtransaction" to validate the transaction as per this use case on the wiki (very bottom of the page): https://en.bitcoin.it/wiki/Raw_Transactions#Validate_a_transaction_without_broadcasting_it

It gave me this error: "Missing scriptPubKey (code -3)"

Does that mean that I didn't sign it properly? Or that I didn't define the outputs properly?

I got the raw transaction from offline version of http://brainwallet.org/#tx so it *should* be well-formed.

I'd still like to do this entirely offline so it would be great to know what's wrong with my raw transaction.