Hi, don here. What board are you riding? I suspect that what you're getting is an artifact of extra wax from the non- flat base- if it's a BS/true3d board, remember that there is a central flat section, and two crescent shaped sections abou in the width you are describing that are the raised portions. This also occurs on the lite3d version, although it probably isn't as noticeable.
This is the case of all non-flat bases, not just us-- easy rider, spoon, TBT- they all require techniques different from traditional flat bases.