When will the Hewlett-Packard board learn the most fundamental lesson of corporate governance and public relations?

That lesson is simple: Disclose all relevant facts, get ahead of the media, and don t turn a one-day story into a media frenzy.

In U.S. public companies, the directors are supposed to serve the owners the shareholders and not management or themselves. Shareholders deserve, and are entitled by law, to material information about the company. Boards should err on the side of transparency. Concealing facts only breeds suspicion, not to mention intense media coverage. That someone might be embarrassed by full disclosure is irrelevant and shouldn t factor in any disclosure decisions.

It was just four years ago that H-P, caught up in a boardroom scandal over director s leaks and spying on reporters, claimed it had learned that lesson the hard way. Then-chairman Patricia Dunn resigned along with two other directors; criminal charges were filed (though those against Dunn were subsequently dismissed) and Congress launched an inquiry, all due, in part, to H-P s clumsy and belated disclosure of the facts. Chief Executive Mark Hurd, who escaped any blame in the affair pledged to restore ethical standards and do better. And it seemed he did, driving up H-P s profits, revenue and share price.

Hurd was forced to resign last week, ostensibly for filing false expense reports amounting to about $20,000. H-P deemed this sum not material, which is beside the point. Anything related to Hurd s departure is plainly material, since on Monday the news shaved $8.7 billion off H-P s market value.

So why did the board ask Hurd to resign? The reason, obviously, is an actress, reality-TV contestant and corporate consultant to H-P named Jodie Fisher who accused Hurd of sexual harassment. Fisher has certainly emerged as the star of a reality TV soap opera far more gripping than any part she was offered in Hollywood. You don t hire celebrity lawyer Gloria Allred unless you re courting the glare of publicity and fame, however short-lived. Surely Fisher s declaration that she was surprised and saddened by Hurd s resignation ranks as one of the most disingenuous remarks to have emerged from the affair. So what was her intention? A made-for-TV movie deal and a line of designer jeans?

H-P hired a law firm to do its own investigation and has exonerated Hurd of sexual harassment, saying he didn t violate H-P s guidelines, even while refusing to disclose Fisher s allegations or H-P s findings. As a result, H-P shareholders have no way of evaluating the validity of H-P s claim. Hurd did reach a settlement with Fisher, the terms of which have also not been disclosed. Both Hurd and Fisher have said no sex was involved. So what was the basis for Fisher s claim? (A spokesman for Hurd declined to comment. Allred said Fisher declined to comment, as well.)

Apart from the expense-report issues, exactly what services was Fisher performing for H-P? The company said she was an outside marketing consultant, and its general counsel indicated she may not have provided all the services she contracted for. But what were those services, and what were Ms. Fisher s qualifications? Her resume doesn t include an M.B.A., to put it mildly, although it appears she did work in real estate and in sales for Xerox in addition to her movie work and appearance on NBC s Age of Love. Supposedly she was a glorified hostess at H-P sales events, making sure big clients got face time with Hurd. Who hired her and why, based on what qualifications?

Hurd s alleged expense account abuse can t be evaluated without knowing the context of Fisher s relationship to H-P and Hurd. Like most CEOs, Hurd apparently didn t even prepare his own expense reports. It could have been a simple mistake or misunderstanding, for which he surely wouldn t have been discharged. If he had a motive to conceal Fisher s role, that s another story. But if so, what was the motive?

The Wall Street Journal reported that a big factor in the board s deliberations over Hurd s fate was fear that the details of Fisher s allegations would prove embarrassing. As I said before, that should be irrelevant. And embarrassing to whom? Hurd, perhaps, but who else? What is the board trying to conceal?

By withholding information, the H-P board is only prolonging the agony and feeding the press a juicy mystery. I suspect the truth, however tawdry, would be a one- or two-day story, assuming H-P is correct that it doesn t amount to sexual harassment. However painful for Hurd and his family, it would soon be forgotten. Delay is only playing into Fisher s and Allred s hands, as a bidding war for Fisher s story will no doubt ensue (even though Fisher signed a confidentiality agreement). By remaining silent, H-P isn t doing Hurd or the shareholders any favors.

When I contacted H-P, a spokesman declined to answer any of my questions and said the company had nothing to add to what it said Friday when it announced Hurd s resignation. He would not say whether, as part of Hurd s agreement to resign, H-P promised not to disclose Fisher s letter or any details of what its own investigation uncovered. In my view, that s not good enough.

H-P still has plenty of questions to answer, including its justification for paying Hurd an exit package worth more than $35 million even while forcing him to resign. Until it does, it is hard to have any confidence in the judgment of H-P s board and as an investor, I d avoid the stock.

Clarification: Leaks from Hewlett-Packard directors began when Carly Fiorina was the company s chief executive. An earlier version of this article failed to make clear that H-P s subsequent spying on reporters took place after her 2005 departure.