If you're hooked on a 110 mm stem, and you need to go shorter, you could always go with a handlebar that has a shorter reach to it. Yes, it's a giant pain in the ass, but it achieves the same end.
theshoemaker, was there any difference in head angle between the 52 and the 54 on the bike you were riding? I've noted a difference in handling going from 73 to 72.5 degrees, so perhaps a different head tube length, head angle or fork rake contributed to the twitch as well...