Problems with spanish location settings

Hello buddies: I have roundcube running in my work. I have around 30 users, and all is working very good, but I have only one problem. When some account try to set the location (int the preferences), to spanish location (español), the messages in the inbox are with de sender and subject in blank. I think this is for the character encoding. I have the database created like the installation readme, and is working very good with the US location. Have u got some solution to the character encoding problem? I have been reading the forum for two weeks, and I only found a patch, from some french buddy, but I first want to ask here. Thanks everybody, sorry for my english, I'm from Argentina... Bye Bye.