I'm sorry you're having this problem.
So, you have a key you have exported from PGP Desktop 10, and it will not import into PGP Command Line 9.6?
What operating system and version are you using when running PGP Command Line?
What version exactly of PGP Desktop are you running?
Is this a public key only, or a key pair (public and private portions)? If it is a public key, are you willing to attach it here?
Is the key block ascii armored?
Was the key generated in PGP Desktop 10, or did it come from somewhere else? If from somewhere else, do you know what software originally generated the key?
Do other operations work properly with PGP Command Line? E.g. can you generate a new key, export that key (or key pair, if you are trying to import a key pair), delete the key, and re-import what you exported?
Thanks.