I agree with Rob, I think your blade may be a bit dull. Give it some laps on the pasted strop before the next shave. I've had the same problem as you have and it's usually been due to a dull razor. Another thing to try is to reduce the angle on the razor when doing your neck to just slightly off your skin (like 5-10 degrees). Another test to see if it's the razor is to have a DE with a new blade handy and when the straight doesn't cut, try the DE and if the DE cuts, then it's probably your straight.