sticky references

Hello
I am saving a dhtmlxCombo object from the grid in a simply Prototype JS hash object. However, it may be my obtusness, after I save that object into the hash if I retrieve that custom combo again and clear it it clears it from the hash. This should not be possible, correct? Somehow dhtmlx code if “finding” all references and clearing them. Even when I just get the keys of the custom combo and store it as a JS array, they get cleared when I clear the on the custom combo. Is this possible, now do I stop it or disconnect the references?