Try this....found it on another board, and it worked for me:
Once in your Blackberry browser Go to Options->Browser Configuration-> and keep the Emulation Mode as Blackberry
Then Go back to Options then go to General Properties and UNCLICK the "enable cursor in column view" radio button.
And I probably already had this but I'm assuming you need to have Column View as your viewing preference when logged into Outlook Webmail.
This allows me to open AND REPLY to my work email. It doesn't even have the "sent from Blackberry Device" footer on the emails.