Lexar Media ( LEXR) plunged 29% late Tuesday after the maker of flash memory cards warned of a steep fourth-quarter earnings shortfall. The Fremont, Calif., digital media manufacturer said it expects sales for the quarter ended Dec. 31 to handily beat Wall Street's estimates, coming in at $255 million to $260 million. That's up from $177 million a year earlier and well ahead of the Thomson First Call consensus estimate of $228 million. But Lexar said it expects to lose 44 to 48 cents a share for the quarter, reversing the year-ago earnings of 21 cents a share and falling short of the Wall Street estimate, which called for a 2-cent profit. The company cited high costs and steep price cuts. Lexar expects to post full fourth-quarter numbers Feb. 3. Late Tuesday, its shares dropped $1.87 to $4.50.