"snuck" isn't a word:
iago@Slayer:~$ echo "snuck" | aspell -a
@(#) International Ispell Version 3.1.20 (but really Aspell 0.50.5)
& snuck 15 0: snick, snack, sunk, Zanuck, suck, snug, stuck, sink, sync, snark, sneak, snook, sonic, sank, snicker
Whereas sneaked is:
iago@Slayer:~$ echo "sneaked" | aspell -a
@(#) International Ispell Version 3.1.20 (but really Aspell 0.50.5)
*