are you using Internet Explorer 8 beta? If so go back to IE6 until they get the bugs out of 8 (7 is far worse IMHO

)
I downloaded IE8 Beta and had all kinds of weird things happen in outlook express including all messages not showing which freaked me in terms of business

Only the subject/sender showed but message body was blank
as well as instant opening as soon as I opened OE...I usually have a 30 sec delay before mail auto opens so I can weed out spam.
as soon as I went back to IE6 all was resolved