said by RobNyc:1 MBP running 10.8.5 haven't updated to 10.9 yet prob will in a few days, updated my older MBP first to see if I saw any issues with the user experience but i only have iChat/iMessage on my main MBP that runs 10.8.5
Unless you have non-standard applications, you should upgrade sooner rather than later. Compatibility between ML/Mavericks is pretty close, but iMessage is improved with every OS X update.
said by RobNyc:Yeah I have closed all conversations on iPhone & iChat. Sorry when I meant SMS was actually imessage as @me.com only works via iMessage mode.
When the new conversation started, did you initiate it or did the other party? If they're sending it to your @me.com address, your iPhone/Mac will start using that as the return address as well.
As for the @me.com over SMS - it's actually possible to receive a SMS from an email address. I saw it rarely with early versions of iMessage, but I don't think it happens anymore.
Also, just curious - why does it matter that it shows up from the @me.com address? If the receiver's contacts are set properly, they shouldn't be able to tell the difference.