Are you making sure that the information you are entering is absolutely correct...

Is it all numbers separated by dashes? Don't list it in here, I am just wanting to make sure...

If it is alpha numeric, then sometimes you have to verify if that is a 1 or l or I as well as O or 0

The way I test this is usually to copy and paste the code I receive into the Windows Notepad...

Notepad as a times type font, and it is much easier to distinguish the characters.