6233 question... ringtone saved in memory card.

I noticed whenever I remove the memory card from 6233 the ringtone I set in my profile will be reset to "nokia tune" - if the ringtone is saved in the memory card. Is this normal? And is there anyway to overcome this problem, or do I have to save all the ringtone files in the phone memory?? - which is hardly enough for mp3 ringtones. Thanks guys.