But this is for messages, whereas I'm just creating transactions here
I should not have to deal with the messaging protocol
Maybe I misunderstand the purpose of the tools but the blockchain.info/pushtx page seems to claim exactly what I understand:
Broadcast Transaction
This page allows you to paste a raw transaction in hex (i.e. characters 0-9, a-f) this will then be checked it is valid and transmitted over the network.
And yeah I found the hex transactions on the wiki, and mine is similar. That's why I don't get what happen
Edit: I just realized that (without the header) bitcoind returns "TX rejected (code -22)"
So it seems that the format is correct, but something is not ok
Maybe it's something to do with the signature like you said...