nothing is wrong with them.. they are yorkies as well.. their ears just aren't up like the 'standard' calls for!
it doesn't make a difference really.. unless you are showing or if you want that look. my Mom's yorkie has floppy ears.. and my Avery's ears stand up.. they are both adorable, just different!
(if you like the ears up.. this is just another reason to buy from a great breeder-they will usually trim the ears and start them on their way to having their ears stand up!
)