Hello
I've recently succeeded in compiling Pd-extended 0.41 (from svn) for my linux 64bit machine and encountered this old garray_gfloatarray problem (half-time playback etc). It seems like d_array.c is using the function, both in my svn copy and the released tarball. I replaced d_array.c with the one in svn head, compiled, and everything seems to be fine, so far.
Hopefully someone with some more insight in the pd code could take a look at this, and if it looks like it's doable, patch/replace the d_array.c in current extended.
regards, Johannes