is my camera too heavy for my tripod

i recently bought a gitzo gilux weekend tripod. weighs about 2 lbs. it came with a velban PH-253 ballhead. the guy i bought it from said that the velban was really for a p & s. so i got a manfrotto 486RC2 ballhead. i am using a rebel xt
i have a more substantial tripod but the gitzo would be for traveling.

i noticed that the 486 on the heavier tripod was fine. when i put the 486 and rebel on the gitzo, it drooped a hair after tightening and removing my hand. i've been able to solve this by tightening the 486 as much as i can.

is this ballhead and camera too heavy for the gitzo??