The private messaging system has been upgraded to support conversations (like topics in our forums) rather than one-way messages.
All your old messages have been automatically converted into the new messaging system. You may find some of your messages with other members have now been streamlined into one conversation. In case you have trouble finding some important messages, you will also notice a link to view your messages in the "old" system.
If you have any questions, notice some issues in the new system, or need help with it, then please post away here!