F5 Networks ( FFIV) expects to restate its financial statements for the past five years to reflect improper accounting for stock options, leading the switch maker to delay the release of its fiscal third-quarter results. F5 said a previously disclosed review into its stock-option grants turned up at least one occasion on which the accounting measurement date for option awards differed from what was supposed to have been recorded. As a result, the company plans to restate results from fiscal 2001 through the first two quarters of fiscal 2006. The company hasn't yet determined the amount of the adjustment. F5 said it won't be able to publish its June quarter results -- which were scheduled for release Thursday -- until the review is completed. The company said it is "unlikely" the review will be done in time for it to file its quarterly report by the Aug. 14 deadline. The company did say that revenue for the fiscal third quarter totaled $100.1 million, up 37% from $73.1 million a year earlier. Analysts polled by Thomson First Call expected revenue of $97.3 million. For the fourth quarter, F5 forecast revenue of $104 million to $106 million, which is above analysts' current target of $103.4 million. Shares of F5 recently were down $1.95, or 4%, to $46 in after-hours trading.