Query remote DICOM server works but unable to retrieve image

Hello: I am new to this product. I have been working to configure it for a couple of weeks now and interface it to PET scanners, CT scanners and imaging workstations. I have been successful in performing Queries of the remote DICOM servers and seeing the lists of patients but every time I attempted the "Copy to Destination" in order to retrieve images, I crashed the remote server and/or Conquest froze. Can anybody please help? Thanks,