Microsoft is set to make changes in the way that Internet Explorer handles dynamic content like Flash or QuickTime. In the next round of security patches (due on 11 April), the company will incorporate the changes that it has incorporated as a result of its patent dispute with Eolas Technologies.

Microsoft has already made these changes available as an optional IE patch, but now they are being rolled into IE's next security update, which will make them effectively mandatory for most users.

"Currently that update is in the testing phase and could be released as early as April," said Stephen Toulouse, security programme manager with Microsoft's security response centre. "But of course, that isn't final," he added.

There has been some confusion over the date of this next release. Earlier this week, Microsoft's Customer Support Services group published a note saying that the changes were expected on 11 April, but that announcement was pulled, because that date is "not finalised," Toulouse said.

In August 2003, an Illinois court awarded Eolas US$521 million in damages for Microsoft's patent violations. Though Microsoft is appealing this ruling, and challenging the validity of the Eolas patent with the US Patent Office, the court ruling forced Microsoft to make the changes or risk being found in contempt of court.

The ActiveX changes will gum up the way some web surfers interact with dynamic content by forcing them to click on a pop-up "tool tip" dialog box before being able to interact with things like Flash or QuickTime.

Microsoft, Apple Computer and Adobe Systems have published work-arounds for the changes, which means that websites that have coded these work-arounds will appear as normal to IE users.