Was going to make a similar suggestion. Perhaps try a skullcap (or do-rag) that has flat lock stitching to minimize effect of the joints in the fabric seams. I wear one of these Cortech liners and it works great. If you have a cloth do-rag with prominent seams stitched together it can create a seriously painful hot spot.
http://www.cortech.net/inc/sdetail/j...dliner/166/558