Google renamed and upgraded its Personalized Home Page this week, but one thing the update couldn't shake was a bug that began upsetting many users last Thursday and persisted until yesterday.

The bug caused the free service, which lets users turn 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 page – now called iGoogle - with syndicated content feeds, as well as with ‘gadget’ applications, to make it their hub for web content, online services and applications.

A source familiar with the issue 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 Thursday morning with reports from upset users, and Google, after acknowledging the problem, didn't declare it fixed until almost 36 hours later.

However, over the weekend, reports kept flowing into discussion forums of users saying the fix hadn't reached their pages, and continued throughout Monday, even as Google's Marissa Mayer, vice president of search products and user experience, hosted journalists in the company's headquarters to unveil the improvements to iGoogle.

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.

By Wednesday, the main 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."

A Google official who posts under the name Google Guide Jaime in that discussion forum gave his most recent update on Tuesday, and acknowledged the resurgence of the bug at that time. "We've been keeping a close eye on this thread and are continuing to investigate the remaining missing homepages as well as the recent reports from those who've just lost your homepages in the past few hours," the official wrote.