Android ContactId may change?

I wrote an application working with contacts and store some data in db using contactId a开发者_C百科s key. Being far from computer (terrible english?) I noticed that data tied on a contact is gone. Can it possible that contactId for contact is changed by Android (or any application?). Thanks

The CONTACT_ID is not durable and may change. LOOKUP_KEY is supposed to help with this, but I have not played with it yet.