Problem with BlackBox 2x1 DisplayPort switcher

Hoping that this is a reasonable place to post this...

The issue is that I cannot get any output from a new BlackBox 2x1 DisplayPort switcher.

2 Macs:
MacBook Pro15-inch, Mid 2009
Mac Mini Mid 2010
both running Mac OS X 10.7.4 Lion.

Display is a Dell U2212HM.

Switcher is a brandy new BlackBox 2x1 DisplayPort Switch (AVSW-DP2X1).

The Macbook Pro is connected via a 3 ft TecNec DisplayPort to Mini DisplayPort - Male-Male cable (MDISP-DISP-3).

The Mac Mini is connected via a Gefen Mini-DisplayPort to DisplayPort Adapter (ADA-MDP-2-DPF) and a Gefen 25 ft DisplayPort Cable.

The Switch is connected to the monitor via a TecNec 1 Meter DisplayPort 1.1 Cable (DP-1M).

Neither machine sees the display - it does not show up in System Preferences > Displays on either machine.

Both machines have no trouble with the display when each is directly connected, all is perfectly normal.

The DisplayPort - DisplayPort cable connecting the switch to the monitor has been swapped out - both are brand new.

I've tried both Auto Select and DisplayPort as Sources on the Dell.

BlackBox support, while professional as always, offered only that "it's probably the adapters, it was built for straight DisplayPort use"...

Is anyone using one of these boxes successfully?

Any thoughts?

I can't find a BlackBox forum...

Thanks!