I found out the solution to this problem from another forum for mac users. Credit goes to the poster(can't remember his/her name).
Launch your Safari 4 and log in to your Hotmail Account
Open up Preferences
Under Advanced tab, check 'Show Develop menu in menu bar'
Search if Develop is available in your menu bar(top of your screen where you can find File, Edit and View etc)
Under Develop drop-down menu, open up User Agent and select Firefox for Mac
Voila! It should work fine now and enjoy reading and deleting your emails in Hotmail!
Hope this works for you as it worked well for me