I freakin' hate that when I click the music or radio tab in WMP10 that I'm not automatically logged in based on the Passport account linked to my Windows login. It looks like it logs me in automagically if I browse there with my MSN browser, so I'm guessing that this is WMP10's fault. What's the point in trying to push a single sign in service to tie everything together if you're not going to set a good example in your own software by leveraging the tie-in? Not only that, but if I check off the “Sign me in automatically” box during the sign-in process, it doesn't remember me that way either.

I know I can't be the only one frustrated by software that sucks at doing something that seems so core to its success. :P