Too close??

First let me describe my grow setup
A 2.5 ft high 1 ft accross cylindrical blue laundry hamper. It is lined with white paper and a white towel on the bottom. The pot is 6 in high and with the lights being mounted on top, the top of the plant is maybe a little over a ft from the light. The light is three 23W ("100 watt incandesent equivilant&quot CFLs. I cover the top of the hamper with a black shirt and all light is sealed.

What ive been noticing is a few brown spots on the tips of some of the leaves, not the topmost either. For the most part the plant looks lush and healthy. When I unvail the shirt to water or check on the plants it is pretty warm in there but not burning hot. Am I burning my plants?? I have no real ventilation but I know that it is not airtight in there as plants can breathe through a shirt.

You need to take some pictures and post them.

lol you think your plant is breathing through a shirt!
your plant is probably only getting cool fresh air when you open the hamper to water them/ check on them.
cfls are fairly cool burning lights but when you seal them in a hamper with no real circulation the heat can really build up.
You really should cut a hole at the bottom side of the hamper with a cpu fan blowing in and another one at the top blowing heat out.
that'll keep you around the right temp, if not atleast 5-10 degrees cooler. you need fresh air if you want to grow a nice plant. period.