The Morrowind font included in Main Font Replacement (http://skyrim.nexusmods.com/downloads/file.php?id=95) doesn't have accent at all - it's not compatible with the french (my native language ;)) version of the game. I found a font pack which happens to include a accented version.
Thanks to Yanek who wrote a short and comprehensiv tutorial on font conversion there (french only): http://forum.wiwiland.net/index.php?/topic/51836-interface-polices-personnalisees-et-tutoriel/page__pid__692567#entry692567
It should be fine for both french and spanish version of Skyrim
PS: as I'm playing right now in english, I couldn't do extensive tests but the accents display correctly when I rename enchanted items
Installation========
Just extract the archive in your Skyril folder, or install it via Nexus Mod Manager (I recommend)
Update===========
04/02/2012=>v1.1. Accented capital letters fixed, everything should be fine