I filed I-130 for my parents in April 09 which is still pending. They have 5 years multiple visa and they been here 4-5 times already. Is it ok for them to visit for a month again while their I-130 is still in pending status?
The answer is it is unlikely, but not impossible, that they will be permitted entry if CBP finds out about the I-130. If it were my own parents, I would probably not take the chance.