VST Link mac to mac (using built in optical in/out)

Hello!

Is anybody use VST Link mac to mac (using built in optical in/out)?
In my case, iMac intel Cubase 5.52 <–> macbook intel Cubase 5 AI is unstable work…
On iMac I use agregate device (built in optical - for VST Link, Apogee Duet - for listen)
OSX 10.6.5 on both computers