Hi! I wonder if this is a bug. I created a static A/R model, and in the middle of specifying some criteria I used the same static model with findByPk. When I went back to using the first model, all criteria were lost.
$model = ARModel::model()
->validItems(); // a simple scope
var_dump($model->getDbCriteria()); // criteria is ok here
ARModel::model()->findByPk(1);
// criteria will be LOST here
// The effect of the validItems() disappears
var_dump($model->getDbCriteria());