Hmm wish I could help. The only times I get so sticky roots are when something has sort of disturbed the natural balance of my scalp and it usually goes away after a few days. I haven't paid particular attention when it happens to know what causes it. I think I sometimes get it when I travel by sea, probably the sea air and sun. O_o
Maybe you should try to avoid things that may cause your scalp to become more greasy, like conditioning your roots, washing your hair with warm water and maybe eating fatty foods too. If it's because of your scalp maybe you shouldn't use a shampoo that dries out your scalp too much, it may cause it to produce more oil instead.
Just making suggestions.