GnuPG from Windows to Linux

Hello List, first i tried Windows Version of GnuPG (WinPT) and transfered the public key to the keyserver and it worked. Then i installed gpa and gpg to my SuSE Linux 8.0. After that I wanted to import the secret key from the cd, where i secured the keys (windows-Version), to the Linux-System, but it does not work. The only thing, i can do, is to create a new key (the same name and passphrase and key-length, but another day) with a public and a secret part, but i fear, that the Linux-Version and the Windows-Version of the keys are different now. What did i wrong? Or am i wrong? Is there a possibility to transfer the keys from Windows to Linux? with regards, Chris