Thanks Murkurie.
RoMee, I tried it, and it's working fine for me. If I click on an email from IE9, without windows live mail open, it opens the program minimally, and creates a new email with that address. By that I mean it creates only the new email window, it doesn't bring up my inbox and everything. If its already open, it just creates the new email. No crashing. It's possible they might have updated WL Mail to work with IE9 and you're using an outdated version. Then again maybe not, check what version you have from Help>About. Mine is version 14.0.8117.0416. If thats your version, I dunno why its not working for you. Maybe try reinstalling Mail. It could also be a bug thats different between 64 and 32 bit versions, if you're using 32 bit.
Edit:
Another thing you might want to check, in Control Panel\Programs\Default Programs, make sure all 4 default options for WL Mail are checked.