To make sure: Don't sign the transaction.
Also I'm sure you know this already but people will be able to see all addresses in that transaction.
You've lost me, I don't see an option to enable "view transaction before signing".
At any rate, this problem hasn't occurred since.... very strange.
If it's gone then I guess it's good . Though I still am curious of what caused it.
That option is listed under Tools > Preferences. It's been there for a long time. Enabling it will allow you to double check your transaction instead of getting it signed and broadcasted instantly once you click send and enter your password.