Why are warnings being treated as errors?

When building off of today's (2009-01-02) libdrizzle (and mordred's auto-conf-cleanup), I get:
***
cc1: warnings being treated as errors
libdrizzle/result.c: In function "drizzle_result_buffer":
libdrizzle/result.c:220: error: conversion to "size_t" from "uint64_t" may alter its value
libdrizzle/result.c:233: error: conversion to "size_t" from "uint64_t" may alter its value
make[1]: *** [libdrizzle/result.lo] Error 1
make[1]: Leaving directory `/root/bzrwork/autoconf-cleanup'
make: *** [all] Error 2
***
After running ./config/autorun.sh ; ./configure && make (it happens in the make, obviously).
Now from what I remember, this implies that the -Werror is either being forgotten or ignored, correct?
The drizzle server compiled fine on this same system.

Any idea what's causing this to trip up the system?
(Its a Fedora 10 server w/ an Intel P4)