mail behaving strangely

[aitch]

I have a mobile me account and generally access it from Mail. The folders where I file old mails, are appearing under the idisk icon, and some of my folders have disappeared. I have two trash folders now, on my mac and the name of my idisk, and two sent folders, one for the idisk... i am confused as to what has happened. I generally do not use the idisk for file sharing apart from I do have an ipod touch which is synced to the macbook. Please can you help? I would like it to go back to how it was....and recover the missing mails.... thanks