Works fine here in 10.7.9, and haven't seen any other posts that the behaviour has changed ? Regarding the mixer, I can't recall it's ever been possible, since scrolling there is supposed to be.. well, scrolling...
I'm not sure that's an ideal solution, since most software instruments still will respond to those cc7 events and mess with the mix balance... A midi transformer in the environment should work, an alternative could be to filter the midi cc7 with a midi fx modifier on the instrument channel strips. (The "Control change message 7/10 sets Volume fader/Pan" setting needs to be unchecked in this case)
If you go Logic Pro > Control Surfaces > Bypass All Control Surfaces, does that change anything ? Are you connecting stuff to the "usb hub" ports on the interface ?
Are your firewall settings allowing Logic incoming connections ? Are you using 3rd party anti virus/malware software ? Could you try the behaviour in a new user account ?