Hope people are still monitoring this topic.

I'm attempting to test this out and not having much success. I used two of my own existing addressed to do the test so I can't/won't provide my private keys. Here are the steps I took:

1. New MultiSig Address. Testing a 2-2.
2. Got this multisig address: 3BubMVeGDzvhZyJ1iCS8vpjKgDSfT18Dh1
3. Sent some btc from addr1 to the multisig. This worked.
4. Verified the redeem script. Says 2 signatures from both public keys are required.
5. Signed redeem script with private key of addr1
6. Copied the result of #5 back in to the upper field and pasted in private key of addr2
7. Copied the result of #6 in to Verify page. Shows the original transaction id, checkmark for redeem script, minimum number of signers 2 and number of times signed 2. Shows me the correct output address and the amount.
8. Copied the result of #6 in to Broadcast. TX Rejected.
9. Reattempted steps 5-8 using keys in reverse order. Same result.

So now I'm stuck. Not sure what to do.

Thanks!