Updated from April 27 With its books still under review, Sonus ( SONSE) revealed limited details about the state of its business Tuesday. The Chelmsford, Mass., advanced phone switch maker avoided most financial details during Tuesday evening's first-quarter earnings conference call. But the company said shipments had increased and that its cash pile grew to over $300 million from $293 million in the previous quarter. Even so, Sonus executives shed no new light on the progress of an audit and Securities and Exchange Commission inquiry into its past three years' accounting. The executives reiterated that the review focused on the timing of revenue recognition and that the underlying sales were not in question. The company repeated that it expects to restate its financial results for a portion of 2003 and 2002 and has included periods prior to 2002 in its review. Disappointed by the lack of details or any imminent resolution of the accounting issue, investors sold Sonus shares Wednesday. The stock dropped 41 cents, or 9%, in midday trading to $4.25. Sonus said in early February that it was examining its revenue-recognition procedures going back two years after firing several nonexecutive employees for unethical behavior. That disclosure knocked the stock to the low $5 range from $6.69, a level to which it fell from about $10 on Jan. 20 after first saying 2003 results would be delayed.