Sorry for bumping this old thread, buy it seems that this guide doesn't work anymore, tried to sign various tx from omni and counterparty , tried various services to sign and broadcast , even qt..
getting "There was an error decoding your transaction! Check what you entered!" error on https://blockr.io/tx/push
and "16: mandatory-script-verify-flag-failed (Public key is neither compressed or uncompressed) (code -26)"  on bitcoin-qt

Any idea how to solve this would help.
Thanks