Updated from 12:49 p.m. Shares of LeapFrog Enterprises ( LF) were among the worst-performing technology stocks Tuesday, falling 34.1% after the company cut its third-quarter and full-year earnings forecast far below analysts' expectations. The maker of educational games now expects third-quarter earnings of 32 cents to 34 cents a share, down significantly from its previous guidance of 55 cents a share. Analysts polled by Thomson First Call had been expecting earnings of 61 cents a share. Looking ahead, the company forecast full-year earnings of 40 cents to 60 cents a share on sales of $680 million to $710 million. Analysts had been expecting earnings of $1.19 on sales of $781.4 million. Supply chain and distribution center issues, along with weak sales of its LeadPad product, led to the earnings and sales revisions. Shares traded down $6.21 to $11.99. Cognex ( CGNX) fell 2.6% after the company posted strong third-quarter earnings but warned that fourth-quarter results would fall short of expectations. During the third quarter the computer technology company earned 25 cents a share on sales of $55.4 million. Analysts were expecting earnings of 24 cents a share on sales of $55.9 million. Looking ahead, Cognex forecast fourth-quarter earnings of 10 cents to 14 cents a share on sales of $42 million to $46 million. Analysts had been expecting earnings of 24 cents a share on sales of $56.1 million. Shares traded down 64 cents to $24.10. Shares of inTest ( INTT) fell 46% after the company lowered its third-quarter outlook and warned that it would post an operating loss during the fourth quarter. The maker of semiconductor test equipment expects pretax earnings of 10 cents to 12 cents a share on sales of $19.5 million. Analysts had been expecting earnings of 13 cents a share on sales of $19.9 million. Order weakness that plagued third-quarter results is expected to continue into the fourth quarter, the company said, resulting in a loss. Analysts had been expecting fourth-quarter earnings of 14 cents a share. Shares traded down $3.57 to $4.19.