Small-cap stocks were sharing the broader markets' pain Friday, failing to manage even a fleeting moment in positive territory. The Russell 2000 lost 1.4% to 710.43, and the S&P SmallCap 600 slumped 1.2% to 367.62.Opnext ( OPXT), an Eatontown, N.J.-based maker of optical modules and components for data transmission, got slammed for 38% of its share price at $4.35. The company lowered sales guidance for the third quarter to $66.4 million from a previous forecast of $77 million to $80 million. The average Wall Street expectation was $79.2 million, per Thomson Financial. In addition, Indianapolis' Interactive Intelligence ( ININ) was in trouble after intimating Thursday evening that revenue would be between $29 million and $30 million, short of analysts' prediction of $30.6 million. Shares were losing 16% to $14.01. On the winning side, AmComp ( AMCP), a North Palm Beach, Fla., property and casualty insurer, popped 37% to $12.01 on news that it would be acquired by Employers Holdings ( EIG). Employers Holdings will acquire all of AmComp's outstanding stock for $194 million, or $12.50 per share. EIG will finance the deal with a combination of cash and debt, subject to regulatory approvals. Georgia Gulf ( GGC), meanwhile, leapt up 25% to $5.12 on an announcement Thursday that it reduced term debt by $71.5 million during the fourth quarter of 2007. The balance-sheet cleanup was fueled by a sale-leaseback transaction, working capital reduction initiatives and an income tax refund.