Critical error when updating from alpha 2 to alpha 3

hi. sorry, in advance, for a not super detailed bug report. i just upgraded from alpha 2 to alpha 3 and get a couple of explosion, one minor and one major. not sure if my old multifield fields are now no longer compatible with the new version, or whether this is a bug, or just something with my setup.

once i updated i went into an existing multifield, tweaked some data and resaved it and got this error (far below)

just doing a diff I can see a bunch of stuff changed relating to loading and saving - i do have some hooks and tricks, so maybe if it is not immediately obvious to the owners of this module, I try to figure out if i have some data integrity issue due to making assumptions about the inter workings of this module that are now no longer true (i know, naughty).

also, when i go to the multifield manage field screen (admin/structure/multifield/manage/[myfield]/fields) and click save i get this message

Notice: Undefined index: _add_new_field in _field_ui_field_overview_form_validate_add_new() (line 672 of /Users/andy/web/ro2/modules/field_ui/field_ui.admin.inc).

PDOException: SQLSTATE[HY000]: General error: 1366 Incorrect integer value: '' for column 'field_content_picker_field_er_content_target_id' at row 1: INSERT INTO {field_data_field_content_picker} (entity_type, entity_id, revision_id, bundle, delta, language, field_content_picker_field_content_picker_selector_value, field_content_picker_field_er_content_target_id, field_content_picker_field_er_embeddable_target_id, field_content_picker_field_er_term_target_id, field_content_picker_id) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7, :db_insert_placeholder_8, :db_insert_placeholder_9, :db_insert_placeholder_10), (:db_insert_placeholder_11, :db_insert_placeholder_12, :db_insert_placeholder_13, :db_insert_placeholder_14, :db_insert_placeholder_15, :db_insert_placeholder_16, :db_insert_placeholder_17, :db_insert_placeholder_18, :db_insert_placeholder_19, :db_insert_placeholder_20, :db_insert_placeholder_21), (:db_insert_placeholder_22, :db_insert_placeholder_23, :db_insert_placeholder_24, :db_insert_placeholder_25, :db_insert_placeholder_26, :db_insert_placeholder_27, :db_insert_placeholder_28, :db_insert_placeholder_29, :db_insert_placeholder_30, :db_insert_placeholder_31, :db_insert_placeholder_32), (:db_insert_placeholder_33, :db_insert_placeholder_34, :db_insert_placeholder_35, :db_insert_placeholder_36, :db_insert_placeholder_37, :db_insert_placeholder_38, :db_insert_placeholder_39, :db_insert_placeholder_40, :db_insert_placeholder_41, :db_insert_placeholder_42, :db_insert_placeholder_43), (:db_insert_placeholder_44, :db_insert_placeholder_45, :db_insert_placeholder_46, :db_insert_placeholder_47, :db_insert_placeholder_48, :db_insert_placeholder_49, :db_insert_placeholder_50, :db_insert_placeholder_51, :db_insert_placeholder_52, :db_insert_placeholder_53, :db_insert_placeholder_54); Array ( [:db_insert_placeholder_0] => embeddable [:db_insert_placeholder_1] => 24 [:db_insert_placeholder_2] => 24 [:db_insert_placeholder_3] => curated_content [:db_insert_placeholder_4] => 0 [:db_insert_placeholder_5] => en [:db_insert_placeholder_6] => field_er_term [:db_insert_placeholder_7] => [:db_insert_placeholder_8] => [:db_insert_placeholder_9] => 62 [:db_insert_placeholder_10] => 4 [:db_insert_placeholder_11] => embeddable [:db_insert_placeholder_12] => 24 [:db_insert_placeholder_13] => 24 [:db_insert_placeholder_14] => curated_content [:db_insert_placeholder_15] => 1 [:db_insert_placeholder_16] => en [:db_insert_placeholder_17] => field_er_embeddable [:db_insert_placeholder_18] => [:db_insert_placeholder_19] => 124 [:db_insert_placeholder_20] => [:db_insert_placeholder_21] => 1 [:db_insert_placeholder_22] => embeddable [:db_insert_placeholder_23] => 24 [:db_insert_placeholder_24] => 24 [:db_insert_placeholder_25] => curated_content [:db_insert_placeholder_26] => 2 [:db_insert_placeholder_27] => en [:db_insert_placeholder_28] => field_er_term [:db_insert_placeholder_29] => [:db_insert_placeholder_30] => [:db_insert_placeholder_31] => 2 [:db_insert_placeholder_32] => 2 [:db_insert_placeholder_33] => embeddable [:db_insert_placeholder_34] => 24 [:db_insert_placeholder_35] => 24 [:db_insert_placeholder_36] => curated_content [:db_insert_placeholder_37] => 3 [:db_insert_placeholder_38] => en [:db_insert_placeholder_39] => field_er_embeddable [:db_insert_placeholder_40] => [:db_insert_placeholder_41] => 418 [:db_insert_placeholder_42] => [:db_insert_placeholder_43] => 5 [:db_insert_placeholder_44] => embeddable [:db_insert_placeholder_45] => 24 [:db_insert_placeholder_46] => 24 [:db_insert_placeholder_47] => curated_content [:db_insert_placeholder_48] => 4 [:db_insert_placeholder_49] => en [:db_insert_placeholder_50] => field_er_content [:db_insert_placeholder_51] => 191 [:db_insert_placeholder_52] => [:db_insert_placeholder_53] => [:db_insert_placeholder_54] => 3 ) in field_sql_storage_field_storage_write() (line 514 of /Users/andy/web/ro2/modules/field/modules/field_sql_storage/field_sql_storage.module).