Microsoft last week added more programs to a list of those that could corrupt files stored on Windows Home Server, but gave no timetable for a patch to solve the months-old problem.

"We're working on this," said Steven Leonard, a senior product manager on the Windows Home Server (WHS) team. "Getting this bug fixed is the most important thing we're doing, but quality is the most important thing [for the fix]." Both Leonard and Todd Headrick, the product planning manager for WHS, refused to set a release date for a fix.

In an updated support document, Microsoft said Intuit's QuickBooks and uTorrent, a Windows BitTorrent client, could also ruin files saved to a shared folder on Windows Home Server. Previously, Microsoft had issued a list of seven software titles, all company-produced programs, that put data at risk, including Windows Vista Photo Gallery, Windows Live Photo Gallery, OneNote 2003, OneNote 2007, Outlook 2007, Microsoft Money 2007 and SyncToy 2.0 Beta.

In addition, Microsoft added 14 more programs to the list that "have been reported by customers as having caused corruptions." They included Apple's iTunes, Intuit's Quicken, Mozilla's Thunderbird e-mail client and software for Microsoft own music player, the Zune. "However, we have not yet been able to reproduce corruptions," the warning stated.

Microsoft also revealed a new caveat that may put some users' minds at peace: Only Windows Home Server systems with multiple drives exhibit the flaw. "This issue only affects Windows Home Server systems that have more than one hard disk drive added to the server storage," said the revamped document. Windows Home Server is designed so that users can easily boost storage space by adding additional internal drives, or attaching external drives to the computer.

The data corruption issue with Windows Home Server goes back more than two months, when Microsoft first acknowledged that under some conditions, editing a document, image or e-mail stored on the server corrupted the file, effectively destroying it. About a week later, Windows Home Server product managers claimed that the bug cropped up only when the server was under an "extreme load" as it copied large files.

The revised support document now omits any mention of "extreme load." Headrick explained why.

"We removed it because it was kind of nebulous about what that meant," he said. "There are a wide variety of circumstances where we've seen [corruption] when the server is not under heavy load. It's really about the application and how it writes data to disk."