This appears as an attempt to install the same architecture and version of a package that is already installed. This installation overwrites this package.
When upgrading a system with the Entire Distribution plus OEM Cluster, the following packages seem to be added twice:
SUNWolinc
SUNWxwdim
SUNWxwinc
SUNWxwman
SUNWxwpmn
SUNWxwsrc
SUNWolbk
SUNWoldim
SUNWolman
SUNWolsrc