In 0.6.6 (Ubuntu hardy) I used the following configuration to connect succesfully to my school's network:

Security: WPA2 Enterprise
EAP Method: [default, don't remember which]
Key type: [default, don't remember which]
Phase 2 Type: [default, don't remember which]
Identity: myusername
Password: mypassword
Anonymous identity: [blank]
Client Certificate File: mycertificate.cer
CA Certificate File: (none)
Private Key File: (none)
Private Key Password: [blank]

After upgrading to 0.7.0 (Ubuntu intrepid), I have tried every possible configuration in the new "Connect to" dialog. This is my best bet, but does not work either:
Security: WPA & WPA2 Enterprise
Authentication: PEAP
Anonymous identity: [blank]
CA Certificate: mycertificate.cer
PEAP Version: Version 1
Inner Authentication: MSCHAPv2
User Name: myusername
Password: mypassword

Attempting to connect simply fails and returns me to the "connect to" dialog. To my non-programmer-eyes the problem could seem to be something about the "Client Certificate File" option no longer existing?