Why is my CWB so sticky on rails and ramps????

I have a 07 CWB transcend platty that I was trying to use at OWC but it was soooo sticky... when it would first get on rails or ramps it would stop for a second! The ramps were very wet and I had no fins on. It got so bad that I had to strap on my old hyperlite and slide that. I was thinking about going over the bottom with a light grit sandpaper... What else can I do???