Disabling or uninstalling a node-type module (e.g. Forum), or removing a node type, results in "undefined index" notices

Repeatable: always

Steps to repeat:

1. Install fresh Drupal 7 site
2. Enable Forum.module
3. Disable Forum.module
4. Go to Reports->Field list. These notices are listed:
   

   • Notice: Undefined index: comment_node_forum in _field_ui_bundle_admin_path() (line 320 of /home/medieva/public_html/skplus/usdkexpats/modules/field_ui/field_ui.module).
   • Notice: Undefined index: comment_node_forum in field_ui_fields_list() (line 35 of /home/medieva/public_html/skplus/usdkexpats/modules/field_ui/field_ui.admin.inc).
   • Notice: Undefined index: forum in _field_ui_bundle_admin_path() (line 320 of /home/medieva/public_html/skplus/usdkexpats/modules/field_ui/field_ui.module).
   • Notice: Undefined index: forum in field_ui_fields_list() (line 35 of /home/medieva/public_html/skplus/usdkexpats/modules/field_ui/field_ui.admin.inc).
   • Notice: Undefined index: forum in _field_ui_bundle_admin_path() (line 320 of /home/medieva/public_html/skplus/usdkexpats/modules/field_ui/field_ui.module).
   • Notice: Undefined index: forum in field_ui_fields_list() (line 35 of /home/medieva/public_html/skplus/usdkexpats/modules/field_ui/field_ui.admin.inc).

5. Uninstall Forum.module
6. Go to Reports->Field list. Notices are still listed, although now only 4 instead of 6:
   

   • Notice: Undefined index: comment_node_forum in _field_ui_bundle_admin_path() (line 320 of /home/medieva/public_html/skplus/usdkexpats/modules/field_ui/field_ui.module).
   • Notice: Undefined index: comment_node_forum in field_ui_fields_list() (line 35 of /home/medieva/public_html/skplus/usdkexpats/modules/field_ui/field_ui.admin.inc).
   • Notice: Undefined index: forum in _field_ui_bundle_admin_path() (line 320 of /home/medieva/public_html/skplus/usdkexpats/modules/field_ui/field_ui.module).
   • Notice: Undefined index: forum in field_ui_fields_list() (line 35 of /home/medieva/public_html/skplus/usdkexpats/modules/field_ui/field_ui.admin.inc).

7. Enable Forum.module
8. Go to Reports->Field list. All notices are gone.

Environment:
OS: linux
Database: MySQL version 5.1.56-log
Web Server: Apache version 2.2.21
PHP version 5.2.17
Drupal 7.9