Accessibility fails on IE8, IE9, IE10

Hi, I'm building content in Flash using Accessibility.active to detect if a screen reader software is running.

The content has 2 versions. So if accessibility.active returns true then version1 is displayed else version2 is displayed. With some computers running Windows 7, Windows 8 with IE8, IE9, IE10, accessibility.active returns true even if there is no screen reader running. Thereby, showing the accessible verison of the content.

All accessibility settings in IE and windows control panel are turned off.

This issue is not faced in Firefox.

Can anyone shed light on this?

Thanks in advance,

Shamil.