Not 100% sure what you are trying to do – but you should probably stay away from the import/export key functionality. It’s not intended for general use, it’s only for some very special scenarios.
Can you please explain what you are trying to achieve, i.e. what is the situation you’re testing out?
If it’s about sharing encrypted files within the team, you should look at the key sharing functionality. There’s a introductory video about that as well via http://www.axcrypt.net/ .