You are running Sametime using the Sametime Proxy with iNotes on XenApp 6. In some cases, chat windows fail to open in Internet Explorer 8 and the following error occurs:
Resolving the problem
1. Open Group Policy (gpedit.msc), Computer Configuration.
2. On the right hand side, expand Windows Components, Internet Explorer, Internet Control Panel, Security Page.
3. Choose Site to Zone Assignment List and click the Show... button
4. Insert the domain names of the Sametime and Proxy servers and assign the value "2" to set these servers to the Trusted Zone. Click OK.
5. Go to the Compatibility View (Windows Components, Internet Explorer, Compatibility View).
6. Enable the Use Policy List of Internet Explorer 7 sites setting, click the Show... button, and then insert the Sametime Proxy Server domain name. Click OK.