Android :: Accessing Contact Phone Numbers - Corresponding ID

I'm trying to adapt my application (Personalytics) for the brand new Android 2.0, however I'm facing an issue while accessing contacts' phone numbers. What I need to do is to retrieve the name associated to a stored contact based on his/her phone number. At present I'm doing this in two steps:
1) from a phone number I get the corresponding ID of the stored contact (if present)
2) I retrieve the contact's name based on that ID

I managed to use the correct CONTENT_URI for reading contacts by using reflection to be fully compatible with Android 2.0 (ContactsContract.Contacts.CONTENT_URI) and the previous versions (People.CONTENT_URI). Now I'm trying to do the same for Phones.CONTENT_URI (Android <= 1.6) and ContactsContract.PhoneLookup.CONTENT_FILTER_URI (Android = 2.0) which is needed by step 2) mentioned above. But as soon as I try to get a contentResolver by using ContactsContract.PhoneLookup.CONTENT_FILTER_URI I get the following exception:
java.lang.IllegalArgumentException: Unknown URL content://com.android.contacts/phone_lookup

This looks really strange to me, since it should be correct (it is part of the official API)! Moreover, I tried to look at the "API Demos" project, in particular to the classes:
com.example.android.apis.view.List2 com.example.android.apis.view.List3
which are still using the deprecated People.CONTENT_URI and Phones.CONTENT_URI and thus no data (i.e. contacts) is loaded (of course I have sample contacts in the emulator). Is there another approach I can use to get the name of a contact based on one of his/her numbers? (This must work on all versions of Android).