Cant Enroll Certificate for OMA throguh phone Active Sync

Hi, I am trying to setup OMA for a client and they are using a mobile device.  I ran the Internet and Email wizard and it configured everything properly.  I am able to get in from an external network.  So, I copied the certificate using DER encoded bindary X.509 (.CER) not sure if thats what I should have selected, anyhow.  So, I then copied it to the clients PC and opened active sync.  I filled out all the required infomation to add the certificate.  So then I press enroll.  It sends the phone a message but when they go to accept it it gives an error in active sync that the Certificate name may be wrong or there may be a network issue.  

Anyone help?