go-pear ignoring drive letter in Windows?

After running the go-pear installer, I find that the data, docs and tests directories are where I specified in the interactive setup (on the d: drive). However, all of the packages were installed in the exact same position: on the c: drive instead. So, it looks like half of it honored my entries, while the other half ignored the drive letter. Is this a known problem? Is there a work-around? I really like the idea of an interactive upgrade and installation method, but this is a problem.