I am having some problems creating a customised firmware using RC4.

Previously, I have been creating customised OpenWRT firmware builds that include a C++ application I wrote, as well as some firewall configurations and things like that.  Previously, I have just dumped all of the non-standard files into the 'packages/base-files/default' directory and run 'make' in order to create the firware image.

I have now added to the functionality of my C++ app, and wish to incorporate it into a new firmware build.  I have had to shift development environments between the previous firmware build and the current one, so have set up RC4 on the new platform and copied the non-standard files into the 'packages/base-files/default' as I have always done, however this seems to have no effect on the resulting firmware image - the image ends up being a straight-up OpenWRT firmware without any of the customisations.  I even tried setting up RC3 and making the firmware under it, as this is what I had used previously, but with the same result.

Any ideas on why the firmware customisations would not be working?

Firmware customizations should be done with SDK and ImageBuilder :
1) you build a package for what you want customized (config files, C++ app...) using the SDK
2) you create a new package list for your firmware, add the package(s) built above to it and create it using ImageBuilder