Just updated WP on my linux installation(Linux Mint ‘Nadia’ with kernel: 3.5.0-27-generic #46-Ubuntu SMP) and I’m sorry to say that WP is not able to detect the network interface in the last version either. 
It detects bandwidth pr application, but not showing anything on the Realtime bandwidth page or on the Network Interface page itself.
Main Network page :[attachment=198]
Applications page : [attachment=200]
Realtime bandwidth : [attachment=202]
The original thread with more data: http://whatpulse.org/forums/showthread.php?tid=2822&pid=22486#pid22486
Edit: Added a link to the original thread started with WP 2.1 beta