reversed polarity of momentary switches?

Hi,

I have 3 momentary anti-vandal switches. On 2 of the 3, connecting ground to the - terminal and power to the + terminal illuminates the LED on the switch. On the third one, this doesn't work. I have to attach ground to the + terminal, and power to the - terminal. Has anyone run into this? If I heard Rob correctly in TCSS's 'Illuminated AV switch wiring' video, he said that this could occur. Just manufacturing defect? I am using the correct dyna-ohm resistor.

Thanks
Mike

Must just be that they put it in backwards somehow. Sorry about that but it should work fine just using it like that.