It turns out that GDAL 1.4 framework is not as backward compatible as I had thought. It’s not GDAL’s fault, but the OSX’s fault. OSX versioning doesn’t work well across major versions. A compatibility version of 1 and current version of 2 don’t work reliably – a program built with an older version of the framework that has compat and current versions of 1 will complain about the newer framework being too old. Or I’m just missing something in my understanding of all this.
So, I changed GDAL to be the same compat and current versions, and the installer now retains 1.3 if it exists. This lets older software that uses GDAL 1.3 still work with 1.4 installed. Currently, this includes MapServer with old-style build (not framework build) and GRASS 6.2.1 in my packages.
There are instructions on the frameworks page for reinstalling both 1.3 and 1.4 (and a download link for 1.3).