Head Unit Ignition Switch

[pdoddy]

I bought a pioneer 6900ib head unit and installed it yesterday in my 2007 polo. whenevr i turn off my engine and remove the key my unit stays turned on. the only way to turn it off is to manually do it by pressing the button on the radio. i have swapped the red and yellow wires over as it seems to be the thing to do but this has not helped. any help or advise at all would be great.

Cheers