The problem was first reported to Microsoft, and acknowledged by the company, in April, said George Waller, executive vice president of StrikeForce. Since then, Microsoft has been saying it will fix the problem but has not gotten around to doing it yet, Waller said.

"I've been calling Microsoft every two weeks since April," said Waller, who sent Computerworld the text of what he said were several email exchanges StrikeForce has had with Microsoft on the issue over the past few months. "They keep on saying we are working on it each time we call them," he said.

In an emailed statement, Microsoft told Computerworld that it is looking into the matter. "Our engineering team is actively investigating the claim that this third-party toolbar is no longer working in IE9; upon completion of that investigation, any necessary updates will be provided," the company said.

"Windows customers and Internet Explorer users should know there is no impact to their or browsing experience as a result of this claim," Microsoft added.

Waller said the issue has caused considerable frustration for StrikeForce and the nearly 2 million users of its technology. "Our anti keylogging technology is useless with Microsoft's IE9 browser because of Microsoft," he said. "What we have been doing is walking everyone through removing IE9 and putting IE8 back to work," he said.