hooking up 3 watt LEDS

Interesting... Is your power source rated for 10A?

You might be better off running three in series and calculating your own resistance values. It would result in less heat and greater efficiency.

Mohrenberg;

I've made quite a few AC powered lights out of 3 Watt Cree's.

The resistors are just lowering the efficiency, so you need to eliminate them.

For large arrays, I usually go for 24 VDC to power them (laptop supply).

You can run about 6 in series with 24 VDC ( or 12 @ 48 VDC).

One resistor may be required to limit current of the string to 700ma (for heat).

They will make a very efficient light source.

This is a 9-watt model I made from a switching power supply:
http://www.candlepowerforums.com/vb/showthread.php?t=171588
It replaced a 13 watt compact fluorescent with better color and more light.

LarryDFW

Either you don't have enough power, or you forgot about the polarity.