Strange digital pin behaviour

I changed the pins to output pins and use digitalWrite(pinNum,HIGH). It seems like the pins can't supply much current. If I have an LED connected on pin 13 it appears dim on one atmega168 and bright on another. Connecting a digital pin through a LED and then a 220 ohm resistor, some appear bright and others appear dim. It's got me stumped whats causing the problem. I'm using a USB arduino NG modified to work as a decimelia. I have the original atmega168 that came with that and also three new ones I burned with decimelia bootloader. All the code works fine, they just don't supply much current.