Messenger not using default browser for email

[toasted]

I recently updated to Messenger v4.7 I already had Plus! version 2.02beta. The default internet browser on my machine is Opera 7.1, and I'm running Windows XP pro. My problem starts when I click on an email alert that pops up or when I click on the email hyperlink in the messenger window. Before I updated messenger, when I clicked on email a new window opened in Opera with the requested page. Now when I click on an email alert, MSN has taken upon its monopolistic self to open Internet Explorer. I'd prefer to use Opera for all the better features it has over IE (mouse gestures, loads pages faster, no pop-ups). I have checked and Opera is still listed as my default browser. I couldn't find anything useful on Micro$oft's help site.

Is there some setting in messenger I'm missing? Is there a registry entry that's doing me in?