Having a Small flat on the bit won't make that much difference...Most of my VInlays were done with an Onsrud .25"shank 60degree engraving bit with a .01" flat defined as a VBit in the toolpath, they came out fine.
I agree with Brady...looks like something is loose/binding somewhere.
scott
p.s. Why the offset in the Male?
Oh...JUST saw on Vectric forum that you're using an offset vector as a boundary box