According to an Adobe spokesman, Flash has already been tested by Adobe and should work fine on Safari on Windows. A Web page on Adobe's site that indicates otherwise is out of date, he said.

"The issues with content not working for certain people on certain sites can be any number of small issues such as how a user has their plug-in configured or how the content publishers have created the SWF (Shockwave Flash) content," he wrote in an e-mail. "Additionally, it's possible that a JavaScript detection script may not yet properly test for Safari on Windows, as it's so new, and incorrectly decided that the browser did not have Flash Player."

He continued: "We would expect these issues to decrease over time as Safari is out in the market longer and its usage grows."

Siteseeing and Silverlight

Microsoft, for its part, admits that it hadn't coded its Web sites to support Safari yet.

"We are initially supporting browsers with the widest usage and are evaluating Safari support for the future," a spokeswoman wrote by e-mail. Safari held 5.7 per cent of the browser market in February, according to Net Applications. IE had about 75 per cent, while Firefox had 17 per cent. All of the sites mentioned above work with the latter two Web browsers.

Many Microsoft Web sites do appear to run under Safari. Functioning sites include MSN, its Live.com search engine, and its Windows Live Workspaces blogging platform.

Microsoft's own rich-media player plug-in, Silverlight, is also a work in progress when it comes to Safari. For that plug-in, which competes with Adobe's Flash, Microsoft currntly supports Safari only on Intel-based Macs running Mac OS X. But it is already testing a version of Silverlight for Safari 3.1 for Windows Vista, she said.

As part of the company's renewed push towards interoperability, Microsoft said earlier this month it would make its upcoming IE 8 browser default to a new, standards-compliant way of displaying Web pages.

That will eventually allow designers to build a Web site once and have it work properly with a wide variety of Web browsers, rather than force them to rebuild and painstakingly test a new version for each new browser, as they must do today. But that happy advance is at least several years off.