Hi Support
Hello John,
ASP.NET controls of versions 10.1 - 10.3 are compatible with IE9 through service releases. Version 11.1 (and future versions) are compatible since the RTM. Versions before 10.1 are not compatible with IE9.
To support IE9, I would recommend upgrading your project to a newer version of NetAdvantage.
For more information about IE9 support, please read this blog.
Elizabeth Albert Localization Engineer