Is siebel 188.8.131.52 support for IE9?
Internet explorer version IE 9 is not supported for Siebel version 184.108.40.206
for more detail, Doc Id 1307383.1 – “Siebel Support for Internet Explorer 9 (IE9)”
Oracle Open UI will be supported on IE9 with Siebel maintenance release version 220.127.116.11 onwards. For more details, please see published document: Siebel Support News – Current Edition – Volume 6 (Doc ID 1341153.1)