This is the first time I've been on for ages - mainly to keep up to date with the soap opera that alex is a scammer!!! Not played poker for a while as I had to cash out my accounts to put down on a car. Not a bad little return for a 0.25/0.50 player.
I honestly wouldn't worry about it - if you want to be ultra-careful just uninstall the client and delete your cookies just in case they store anything in them (I doubt it). Make sure usernames and email addresses and personal info are different and you'll be fine.