Taking a particularly big hit today was American International Group ( AIG) after the New York insurance giant disclosed that it had severely underestimated the valuation plunge of its super senior credit default swaps, or contracts that shift the risk of credit default to the buyer. AIG now has the portfolio's gross cumulative value sliding $5.96 billion vs. the previously stated figure of $1.6 billion, having recently factored in certain harmful "structural mitigants, such as triggers that accelerate amortization of the more senior CDO collateralized debt obligation tranches" that weren't "adequately quantif ied " before. AIG explained that it had relied on "market prices, not credit ratings," in its prior method of calculating credit-default risk. As of Sept. 30, AIG valued the total portfolio at $513 million, including $78 million worth of multi-sector CDOs that had "some exposure to U.S. subprime mortgages." Prompting the big valuation adjustment was AIG's auditor, PricewaterhouseCoopers, which cited a "material weakness in AIG's internal control over financial reporting and oversight" regarding that portfolio. AIG shares were sinking $5.37, or 10.6%, to $45.31. BlackBerry maker Research In Motion ( RIMM) jumped $4.76, or 5.3%, to $94.47 following news that the company has signed a deal with Vodafone ( VOD) to add the BlackBerry platform to Vodafone's line up of preferred consumer services. LCA-Vision ( LCAV), a Cincinnati firm that operates LasikPlus vision centers, took a 17.6% tumble to $14.20 on fourth-quarter earnings. Income decreased to $4.1 million, or 22 cents a share, from $5.6 million, or 27 cents a share, in 2006. Analysts were looking for 21 cents a share, per Thomson Financial. Despite the beat, LCA forecast a challenging economic environment for 2008 and announced it had cut its workforce by 16% in anticipation of reduced procedure volume. Salesforce.com ( CRM) added $3.93, or 7.7%, to $54.80 after chatter that the company may be a buyout target, with Oracle ( ORCL) as the potential suitor. Shares of Phoenix, Ariz.'s Hypercom ( HYC), which sells electronic payment solutions, jumped 30.1% to $5.14 after French payment processor Ingenico made an unsolicited bid Friday after the close to buy Hypercom of $6.25 a share. Hypercom CEO Norman Stout announced Monday morning that he had opened discussions with Ingenico and hopes to announce the results "as expeditiously as possible." Hypercom further intends to carry out its acquisition of French transaction firm Thales, a deal valued at $120 million. Elsewhere, Chicago-based CNA Financial ( CNA) also missed sharply with an operating profit of $223 million, or 82 cents a share. Analysts were looking for $1.03 a share; a year earlier, CNA made 91 cents a share. And health insurer Centene ( CNC) was cut to neutral-equivalent ratings at both Credit Suisse and Wachovia following Friday's disappointing earnings report. CNA shares slid 18.4% to $26.31, and Centene was off another 11.2% to $19.03.