In your "one-line-solution", when you valorize $model->album_photocover that you use to compose the save path?
CUploadedFile::getInstance($model, 'album_photocover')
->saveAs($path . '/' . $model->album_photocover);
//____________________________^++++++++++++++++++++++^
ADD I seen now @Telvin Nguyen comment, yep, that's the problem!