Anyone know how to remove a quick key when the DELETE is not available?

I have a Cingular Treo 650 that you cannot change the quick key of Contacts (currently J). When you go back to Edit this, it is locked somehow and your only option is OK or CANCEL at the bottom...and you cannot click the J to change it (no .... under the assigned quick key).

On another Treo 650 (Sprint's) I can delete the key, change the key, etc.

Is this a vendor specific issue or a PalmOS issue or a general bug?