In the future always check the first and last few characters in the address field to make sure. Luckily you managed to save yourself this time 
I wouldn't rely on this: a smart virus would pick up a vanity address from a server, so that the first and last few characters are the same. Also check a few in the middle, or even better: don't trust Windows with money.Windows is fine providing you can trust yourself on it. If not, demote your user account so you're not always an admin on it which will cut a few of the problems (though not all)
And I check the characters of addresses before sending them, it gets better when you send to the same addresses each time as you can remembr patterns between them. General rule of thumb for testing copies of new addresses - check the first FIVE and last FIVE character, it's very difficult for something to be able to produce a vanity address like that in a fast enough amount of time.
Also ensure you double check what you are signing before it is broadcast to check the address doesn't change between that point.
