Hi,
Please check the below note .
Note 838402 - Problems within non-Unicode system landscapes
New releases of SAP NetWeaver and SAP applications based on SAP
NetWeaver, released in 2007 or later, will no longer support new installations of non-Unicode systems. See also the attached customer letter Customer_Letter_64_U.pdf from April 11th 2006 (also available at www.service.sap.com/platforms).
Existing non-Unicode systems are still supported, but due to the intrinsic limitations of non-Unicode code pages SAP recommends a conversion to Unicode, especially when upgrading system to Netweaver 7.0 (ERP 2005) and higher releases.
Problems can occur after any upgrade, even whithout applying new applications, e.g. in case.existing applications are redesigned based on new technologies.
Please also check the below link.
http://scn.sap.com/docs/DOC-28791
Thanks
Rishi abrol