When testing the DHTMLX library with IE9, we found an incompatibility issue that appears when data is loaded from an XML file. To fix this issue, please use dhtmlxcommon.js which can be downloaded here. We have also fixed the problem with drawing of node labels in dhtmlxTree in IE9 Beta.
All component packages, which are available for download from our site, already contain the fixed dhtmlxcommon.js. Users of dhtmlxSuite PRO Edition will receive the link to the compiled dhtmlx.js with applied fixes by email.