The only save that won't open in the sims is the one I want the most, with my estate and all my horses very few of them are actually saved so unless I can fix this somehow it's gonna be bad. Ill have the four new foals and possibly three of the other adults. Needless to say I'm extremely angry/annoyed. I would use colourful-er language but there's no point. So I'm going to be up all night trying to fix it. :'(
24/08/12 update
Horses lost are:
LEC Storm Chaser
LEC Electric Star
LEC Mystery of the night
LEC Shallow Dreams
LEC Storm Chaser
LEC Electric Star
LEC Mystery of the night
LEC Shallow Dreams