By Chris Bulkey of Technology Research GroupTexas Instruments ( TXN) revised first-quarter earnings guidance this week to a range of 48 to 52 cents from 44 to 52 cents and disclosed that it still sees supply constraints, which could impact inventories and margins. What this really means is that the company is having difficulty gauging utilization following a downturn in sales and orders last year. We view the revision to guidance as inconsequential. Cautious comments are the real story. Shares closed Thursday at $24.07, down 52 cents, or 2.1%. Working capital metrics contradict any notion of improving visibility. For full-year 2009, inventory turns failed to show improvement and actually deteriorated slightly (4.52 vs. 4.55 in 2008). Less stringent credit policies bode poorly for revenue recognition. Receivables jumped 40% for the year, while revenue declined by about 17% (contra account was lowered by a fairly substantial amount as a percentage of A/R balance; decision should raise an eyebrow).