MSC Software Corp. (Nasdaq: MSCS) was off by $0.67, or nearly 5%, to $12.85 on heavy volume in after-hours trading Tuesday after the company announced preliminary revenue results that came in below analysts’ expectations. The Santa Ana, Calif.-based software and services provider said it expects to report revenue in the range of $56 million to $58 million for the first quarter ended March 31. Four analysts polled by Thomson First Call were expecting revenue of $64.2 million. The company will report the full results May 9.

Shares of Netlist Inc. (Nasdaq: NLST) fell $0.86, or 14.4%, to $5.11 in after-hours trading Monday after the memory subsystems manufacturer issued a lower-than-expected revised first-quarter guidance. Irvine, Calif.-based Netlist said it now expects to report earnings per share of $0.02 to $0.03 per share on revenue of $37 million to $38 million. The firm had previously issued guidance of $0.07 to $0.08 per share on revenue of $40 million to $42 million. Three analysts polled by Thomson First Call were expecting earnings per share of $0.08 on revenue of $41.2 million for the quarter ended March 31. Netlist CEO Chuck Hong cited operating expenses and decreased customer demand for the revised guidance.

Despite posting record sales and earnings for fiscal 2006, shares of Restoration Hardware Inc. (Nasdaq: RSTO) fell in after-hours trading after the home furnishings retailer missed analysts’ estimates on fourth-quarter earnings. The stock dropped $0.41, or 6.2%, to $6.23 on heavy volume. In other after-hours trading: