Bicycle Mechanics - squeaky head set

i recently purchased a trek 520 for commuting and weeked touring. i'm loving the bike in general, but hve one issue-- i kept hearing this squeaking sound when i rode over small bumps or potholes holes in the road. i couldn't figure out where it was coming from, but sounded like somewhere up front near the handle bars. this morning i sort of twisted around the spacers and the bottom of the headset (cane creek), and when i got back on and rode, the squeaking stopped. then about 4 miles further, i started noticing the squeak come back, but not as badly as before. is it infact my headset? if so, what can i do to fix the problem?
thanks-

Are you referring to the spacers between the headset and the stem? If you can twist the spacers around by hand, your headset may be too loose. Check the side to side play in the fork. There shouldn't be any detectable play. If there is, then get it tightened. You could damage your headset pretty quickly riding it loose.

thanks-
i tightened the headset down (from the allan bolt looking straight down at the head), and the spacers still twist very easily by hand. i don't feel any play in the fork, but this seems strange. i checked the spacers on my mountain bike, and they do not twist at all. the top of the headset, just below the spacers, is able to twist on both of my bikes. does anyone know what is going on here?

Did you loosen the stem before you tightened the bolt on top? If not probably did not really push down on the stem to make it push on the spacers.

thanks kev- that was my problem. it's all good now.

even though i am in engineering i am often fairly inept at dealing with simple mechanical problems....

Dont' worry I did the exact same thing a short while ago, I tightened the top cap.. and took me a min to figure out why the headset was still loose.