Go into the .mis file with notepad, and look for this:
//--- OBJECT WRITE BEGIN ---
new SimGroup(MissionGroup) {
   new ScriptObject(MissionInfo) {
         saveName = "Bedroom";
         name = "Bedroom";
   };
change it to this:
//--- OBJECT WRITE BEGIN ---
new SimGroup(MissionGroup) {
   new ScriptObject(MissionInfo) {
         saveName = "X-Mas Bedroom";
         name = "Christmas Bedroom";
   };
You can also have a space in the christmasbedroom.txt
If you still can't fix it, PM it to me, and I'll do it real quick for you. :)