I only use bamboo. (I do use Addi Turbos in both metal and the natura/bamboo) And I have never had that problem. Maybe you knit on the tighter side? Also, I first started using off brand bamboo needles and they did stick more.
I then switched to Clover/Takumi and really liked it much more. The finish is great and they are just highly polished not coated with a laquer. I have found that the more that I use them the better they get. And I think that the natural oils from your hands make them better and they do not build up.
I have since switched to the new Clover/Takumi Velvet bamboo in both DPN's, Circs, and Single Pointed. And they are far my favorite. The feel and the slickness is great when you knit, your work just slides off the needles, but it still is not as slick as using metal ones.
Hope that helps.