Thanks a lot fore all the help and comments..
As you suggested removed the sata HD , burnt a new DVD and the installation went through all rite

went through the kext installation again ..got all the Hardware woriking.. updated itunes/quicktime/aperture/frontrow..ALL SET.
Now i took a backup of the leopard partition using Time machine.. Jus one silly doubt .. i will be able to restore leopard using the installation DVD in case anything goes wrong again rite ?