Online Contributions - Custom Data Not Saved / Custom Data Should NOT be Retrieved in setDefaults

To recreate these issues:
1. create a custom data group extends Contributions and add a custom field to it
2. create a profile which contain this custom field
3. link this profile to an online contribution page
4. make a contribution and put a value in the custom field

BUG 1: The custom field value is not saved during the online contribution processing

5. Now edit this contribution manually (find contribution >> edit) and fill in a value in the custom field
(the value IS saved properly in the offline edit mode)
6. Now go back to your Online Contribution page w/ reset = 1

BUG 2: The custom field value you entered for the PRIOR contribution is being retrieved and the field is being filled with that value (I assume by setDefaults()). This is the correct behavior for custom data which extends the Contact object - but it is NOT correct behavior for Contribution object data.