I've upgraded from version 2.06.2 to 2.07 today and immediately started getting problems with devices such as XBOX 360 complaining about MTU size - and hence not being able to connect. I downgraded back to 2.06.2 and the problem has gone away again. I checked the MTU size setting whilst using 2.07 and it looked ok - but who is to say that it's actually using the value displayed.

Accessing the internet via a browser on my Mac was fine so obviously something subtle