The great thing is that our commission income has risen steadily each year. If you are in the same industry and a similar position, and your salary is guaranteed (and also higher), I don't see a problem. It;' what we used to call "make sense" lending. However, as your processor noted, this can be a judgment call for the underwriter. Put it this way -- if this lender says no, there are likely to be others perfectly willing to say yes.
In fact, Fannie Mae's guidelines state, "A minimum history of 2 years of commission income is recommended; however, commission income that has been received for 12 to 24 months may be considered as acceptable income, as long as there are positive factors to reasonably offset the shorter income history."