Under some circumstances, sorting vectors introduces !NaNs into them when compiled with optimisations. This does not happen when compiled with -msse2 and apparently only on 32-bit systems. 7.0.2 and earlier didn't introduce !NaNs either, and for the attached programme (requires vector and vector-algorithms), the only difference in the assembly produced by 7.0.2 and 7.0.3 (apart from different unique names) is the presence of some FPU-freeings in 7.0.3's which 7.0.2 didn't produce, likely caused by the fix to #4914 (closed).