Electric mulching lawn mower vibrating

 

My new Black and Decker Model MM275 electric plug in mulching lawn
mower sends quite a high frequency, low power vibration through to the
handle.  My last electric had no vibration (not a mulching mower) at
all.  What could the cause of this be?  Is it possible that this is
just part of the design of a mulching mower?

http://www.blackanddecker.com/ProductGuide/Product-Details.aspx?ProductID%04

JS