Are you running Service Pack 2?  Did you reboot after installation?  On what system?  Some systems requires a reboot before it will work, and some systems may require a different version.  Although OMSA installs a small web server running off of port 1311, IIS should be unrelated and should not impact it at all.
OS: Windows 2003 Standard Application: OpenManage Server Administrator (6.2.0)  Problem:Dell Open Manage does not open the webpage Trouble shooting: 1. I checked Mcaffee HIPS no applications being stopped. 2. Checked Services in Computer Manager.  3. The server is running I.E 6.0 could this be and issue?        
Install of OpenManage Server Administrator (6.2.0) not working