Ha! Good question! There is a different solution depending on whether miasgam meant that the person browsing was too old or the app doing the browsing was too old. Don't know if you can fix either one. You can upgrade your OS if you are still running 4.5
JB
Typically the message that the OP is seeing occurs when the user is trying to view content that uses Adobe Flash. There currently in no Flash for BlackBerry. Reportedly they are working on a release for the second half of 2010.