I would like to add some additional fields to the system template used by the PhoneBook application. I sorted out the system template is defined by ctnmodel.rsc. On N73 there is a SIS stub for the phone book application. With a hex editor you can see cntmodel.rsc is included in this SIS stub - therefore cntmodel.rsc should be upgradable using a PU package.
However, my N73 contains cntmodel.rsc contains localized resource files for the EURO language pack with extensions ctnmodel.r01, etc. These files are not mentioned in the SIS stub module.
As a consequence we call install cntmodel.rsc in the c: drive, but it is not used by the phone book app, because it will find cntmodel.r01 in the z: drive.
If we try to install an update for cntmodel.r01 on the c: drive this fails (component already built-in), because the localized files are not mentioned in the phonebook SIS stub.
I upgraded the N73 to the latest firmware (v4.07220.127.116.11 01-09-2007 RM-133 Nokia N73 (02)).