While registering a hotmail account to the blackberry handheld, there's a term that goes like this:
"Please note that you are required to re-authorize your Windows Live email integration every 90 days. To do this, log into your BlackBerry Internet Service Email account, select your Windows Live email address, and re-enter the password. If this is not done every 90 days, messages from your Windows Live email address will not be delivered to your BlackBerry smartphone until that email address is re-authorized."
If that's the problem..you know what to do
Posted from my CrackBerry at wapforums.crackberry.com