3rd party Sat Nav not staying on while in 'Accessory'

[ajsendall]

Hello all,

I recently bought a 2008 Modeo and fitted a sat nav unit from Hizpo. The original Ford 6000 CD worked as it should, but the replacement sat nav will not stay on when the ignition is switched to 'accessory' unless I use the steering wheel buttons to navigate the IPC menu every few seconds. Also, since fitting the new unit the a/c vents seem to open/close a few times for about 30 minutes after switching off the engine. The seller of the head unit is trying to blame a fault with the car, but as it worked fine with the 6000, that seems unlikely. 
Any ideas what might be causing this other than a faulty sat nav?
Thanks.