Upgrade 10gR1 to 10gR2 – DBUA error

Today I was upgrading 10gR1 to 10gR2 (10.2.0.1) on Linux x86. The upgrade went almost fine (except that I had to install one package and change few kernel parameters) but while running DBUA to upgrade databases, it gave an error:

 

1. Could not get database version from the Oracle Server component. The CEP file rdbmsup.sql does not provide the version directive
2.
3. and
4.
5. Start of root element expected. Upgrade Configuration file
6. 'C:\Oracle10g2\cfgtoollogs\dbua\test\upgrade5\upgrade.xml' is not a valid XML file.

I searched in the metalink and found that this all happens due to customized glogin.sql file which was there in my case also. And removing that customization made DBUA rock