The Mystery of Electro Scientific Industries

Electro Scientific Industries was highlighted as a "home run stock" by Zacks before they reported earnings in January.  The company had a stellar quarter and even raised guidance, but the shares dropped as pointed out by this MF Article.  Zacks has pointed out that its PEG ratio is .55.  Undervalued and growing like a weed?  This stock should be taking off, not tanking.