I suppose you have installed gpsd the wrong way. At least when I read your description how you have done it.
Use MacPorts with the command "sudo port install gpsd +universal" after you have deinstalled your former attemps.
So you get an universal libgps for 32bit and for 64bit. The word universal is a little bit misleading for people new to OS X. Before Leopard
it means the program is usable for PPC and Intel and after Leopard
it means the program is usable for Intel 32bit (i386) and Intel 64bit (x86_64). Rosetta does not exist anymore.
A word to Dave:
It is also misleading when you use in your code ifdefs for wxWidgets 2.9 but in later updates and new implementations forget about this.
In wxWidgets 2.9 the OpenGL behavior has changed as mentoined in the docs:
"Notice that versions of wxWidgets previous to 2.9 used to implicitly create a wxGLContext inside wxGLCanvas itself. This is still supported in the current
version but is deprecated now and will be removed in the future, please update your code to create the rendering contexts explicitly."