Hi John, thanks and yes, I've been communicating with Rory (sales manager). He said his unit works the same as mine but isn't sure if this means both our units are faulty, so he's asked their tech guys to look into it and will get back to me.
Problem is, it's now been almost 3 weeks and I'm still no wiser.
On another forum, two Benchmark DAC 2 owners replied to me saying their units work as described in the manual and have advised me to get mine replaced.
Anyway, thanks again.