LED only working with battery - not with power supply

[Koeffe]

My overdrive pedal is built after this:
http://www.generalguitargadgets.com/pdf/ggg_mbb_lo.pdf

I just got myself at Cioks Double Jack power supply. The pedal works with that, but the LED isn't lighting - only when i'm using a battery. What could be wrong?

[frokost]

Wiring error, most likely. My guess would be that you have connected the LED to the same terminal on the power plug as the red wire from the battery snap. When the power adapter is plugged in, the battery snap is disconnected, and so is the LED. Are the wires connected like this? http://tonepad.com/project.asp?id=35

[Koeffe]

Thanks!!! That was way simplier than I thought... But I'm wondering how I could have done it wrong... I'm sure I triple-checked everything when I built it

[frokost]

Don't we all  .