"I have just installed IE8 and still the search option doesn't work. All I get is a blank line with no search box so what and where is the problem?" a visitor to Microsoft's Explorer feedback page who identified himself as Aviramoff wrote on Thursday -- the same day Microsoft formally released the product.

Aviramoff was among dozens of posters to report significant IE8 glitches.

Another user, Bob, wrote that certain Web sites weren't displaying properly in Explorer 8, including that of online greeting card purveyor American Greetings. "After downloading IE8 I cannot print any card from American Greetings. The message I get is, 'An error occurred during the operation,'" complained Bob.

Microsoft has warned Web publishers that Explorer 8's default support for some new Internet standards may cause problems with their sites. Explorer 8 includes a tool called Compatibility View that lets users view sites built for previous editions of the browser.

But some IE8 adopters reported that even pages built with Microsoft's own Web publishing software, Microsoft Publisher, failed to render properly in the new browser. "I created my company's Web site using the MS Publisher 2007 template. After upgrading IE7 to IE8 my menu tabs and many important images no longer show," wrote a user named Phil Wheeler.

The news wasn't all bad for Microsoft, as some IE8 users said they were more than happy with the product.

"In my first 30 minutes of using IE8 on my Vista Business Edition I am very pleased," wrote Lambert. "The browser opens in a quarter of the time that it did in IE7. Normally I would not bother posting such an effusive comment, but IE8 is that good," Lambert gushed.

Microsoft needs Explorer 8 to be a hit, as the company's Internet Explorer franchise has been losing ground to competitors. Explorer's share of the market has fallen from 75% to 67% in just the past 12 months, according to market watcher Net Applications, while competitors such as Apple's Safari and Mozilla's Firefox have gained ground.