If anyone is using port forwarding with a 300B, be very careful with the new firmware - 1.1.0.2.
I upgraded to this version on a customer's 300B and promptly lost ALL port forwarding. It didn't matter what i did, delete the old forwards/re-create them - no effect. The 300B shows them there - they just don't work!
I had to factory reset the 300B, downgrade to an older firmware, and re-enter all the settings (for some reason while the config backup would load successfully, it wouldn't let me back in). :x
If you do have a 300B, be sure you have an older firmware on hand if you decide to upgrade - just in case.