r.slope.aspect problems

[Matt Knox]

GRASS users,

I created a surface map with r.surf.idw which appears to contain good data (thanks to Melissa Records for helping me get this far).  This surface map was created at a resolution of 0.5m (which I think is justified because my original elevation data, which I would like to preserve, contains 1' contour intervals).  The optional parameter npoints was left at the default value of 12.

The Problem: