It really depends on what the person's status in the US is at the time of filing for adjustment of status. If one is in valid status at the time of filing and applies for advance parole, one IS able to travel internationally while the AOS application is pending. If one is out of status or unlawfully present at the time of filing, it is not ok to travel internationally, as there is no basis for readmission to the US.
Answered on Apr 16th, 2013 at 7:52 PM