Google has upgraded its Personalized Home Page this week but can't shake off a persistent bug.Google has upgraded its Personalized Home Page, renamed it as iGoogle but still can't shake off a persistent bug.

The bug caused the free service, which lets users turn Google.com into a customised portal, to revert an undetermined number of pages to their default settings or to months-old versions.

The problem rattled users who spend significant time and effort tailoring their Google page with syndicated content feeds, as well as with "gadget" applications, to make it their hub for web content, online services and applications.

A company source said the bug affected "a single digit percentage" of users of this service, which company officials have said has "tens of millions" of users. This means that the number of affected users could range from a minimum of 200,000 to several million.

Discussion forums erupted last week with reports from upset users, and Google, after acknowledging the problem, didn't declare it fixed until almost 36 hours later.

However, reports kept flowing into discussion forums of users saying the fix hadn't reached their pages, even as Google's Marissa Mayer, vice president of search products and user experience, was telling journalists about the improvements to the iGoogle service.

At the time, it seemed that the users still complaining had been affected by Thursday's bug, and that it would be a matter of time until Google rolled the fix to their pages.

However, on Tuesday morning, as the volume of complaints in discussion forums increased significantly, with a new wave users reporting the problem for the first time, it became apparent that the bug had cropped up again and was affecting an entirely different batch of iGoogle pages. And by yesterday tthe main Google thread devoted to this problem had generated almost 700 postings.

The problem is now solved, according to a Google spokeswoman. "A number of Google users had difficulty accessing their settings and preferences on their iGoogle pages over the past day," she said "Users should have their iGoogle pages restored at this time."

In declaring the problem solved last week, Google declined to explain what caused it or how many people were affected, saying only that the bug had been an "isolated incident" and that it had hit "a relatively small group of users." Wednesday, the spokeswoman also declined to provide these details.

However, Google has been hit with bugs and availability problems such as this one with some regularity in recent months in services like the Blogger blog hosting and publishing service and the Gmail portion of the Google Apps suite of communication and collaboration software for organisations.

In this case, it certainly didn't give users confidence in the hosted model, given that a bug affected one of Google's most popular services for almost a week, while senior officials held a press event to tout the latest improvements to the service.

A quick examination of the discussion forums reveals a trail of disappointed users whose confidence in Google has been significantly shaken.

"Google, you have broken my heart. I had such faith!," a user wrote Wednesday morning. "You were my everything, and now ... now I just don't know. It's not like you to be so quiet, Google. Please, just let me know you're listening! Let me know that you care!"