Don't use cvs update when what you want to use is cvs diff - you get the same information, but if you do it the wrong way you end up all sticky.
I learned this the hard way - I kept checking information out, modifying it, and using cvs update to check where I had mods and then when I wanted to check things back in I had to use cvs update -A to get rid of the sticky bit - cursing CVS the whole time...