The company has not officially said -- and Dowling declined to comment on -- whether it is investigating or has found instances of options backdating. However, Dowling did say that the impetus for the company's initial examination of its past grants was in reaction to "general industry concerns about historical options" practices. Those "concerns," of course, are almost entirely related to backdating allegations. When Apple first announced its internal probe, most investors seemed to be willing to give the company the benefit of the doubt , particularly because Apple said it had already cancelled the grant it gave Jobs. But the news of a wider investigation and delayed filings could prove more troubling to investors. Jobs is largely seen as almost single-handedly reviving Apple, and anything that could end his tenure at the company could rock its stock. And that's now a distinct, if slim, possibility -- depending on what Apple and, potentially, federal regulators uncover. At several other companies, including Brocade ( BRCD) and Mercury Interactive ( MERQ), similar options probes have prompted the resignations of executives and board members. Although Apple is the subject of several shareholder suits related to its options problems, the company has not said whether it is the subject of a regulatory probe. For his part, Dowling declined to say whether the company has been contacted by federal regulators. However, when other companies have discovered problems with their grants, the SEC and other federal agencies have generally quickly followed with their own probes. A federal investigation, then, may be only a matter of time. Though Jobs may have returned the options that are under investigation, he did receive something for them. In fiscal 2003, Apple replaced Jobs' cancelled options with 10 million shares of restricted stock worth $74.8 million at the time, which are now worth several times that amount.