i cut the bottom little rubber thingie off the bottom of my skull cap after it dug into my head (probably left a little line too) and gave me a headache the first couple times i tried it out.
after cutting off the bottom (i am assuming yours like mine is just made of some spandexy type thing) it looks ugly as h@ll as i am a poor seamstress and cut it pretty badly, but is so comfy i totally forget i am wearing it.
i wish they made one without the rubberband down around the bottom... it's stretchy spandex, is it really going anywhere