Double "Customize this page" button if user don't have permission to "Change layout"

If a user have the permission to "Use the Panels In-Place Editor " but not the permission to "Change layouts with the Panels In-Place Editor ", the user still gets two buttons in IPE.
Both buttons are labeled "Customize this page", but only one works. The other one returns some raw json data I think:

[{"command":"settings","settings":{"basePath":"\/drupal-7.14\/","pathPrefix":"","ajaxPageState":{"theme":"bartik","theme_token":"-DPTm3ISqK9ISgIK0X_yA4CFX4XGOmk7nJIhTl3ftj0"}},"merge":true},{"command":"initIPE","key":"panel-context-page-test-page-test-panel-context","data":"\u003Cform action=\u0022\/drupal-7.14\/panels\/ajax\/ipe\/save_form\/panel_context%3Apage-test%3Apage_test_panel_context\u0022 method=\u0022post\u0022 id=\u0022panels-ipe-edit-control-form\u0022 accept-charset=\u0022UTF-8\u0022\u003E\u003Cdiv\u003E\u003Cinput type=\u0022hidden\u0022 name=\u0022panel[pane][top]\u0022 value=\u0022\u0022 \/\u003E\n\u003Cinput type=\u0022hidden\u0022 name=\u0022panel[pane][left]\u0022 value=\u0022\u0022 \/\u003E\n\u003Cinput type=\u0022hidden\u0022 name=\u0022panel[pane][middle]\u0022 value=\u0022\u0022 \/\u003E\n\u003Cinput type=\u0022hidden\u0022 name=\u0022panel[pane][right]\u0022 value=\u0022\u0022 \/\u003E\n\u003Cinput type=\u0022hidden\u0022 name=\u0022panel[pane][bottom]\u0022 value=\u0022\u0022 \/\u003E\n\u003Cinput type=\u0022submit\u0022 id=\u0022panels-ipe-save\u0022 name=\u0022op\u0022 value=\u0022Save\u0022 class=\u0022form-submit\u0022 \/\u003E\u003Cinput type=\u0022submit\u0022 id=\u0022panels-ipe-cancel\u0022 name=\u0022op\u0022 value=\u0022Cancel\u0022 class=\u0022form-submit\u0022 \/\u003E\u003Cinput type=\u0022hidden\u0022 name=\u0022form_build_id\u0022 value=\u0022form-2q-pzj92yCrOgM-c88ZYmOKhUOFLLau-Gid7r_g8VMM\u0022 \/\u003E\n\u003Cinput type=\u0022hidden\u0022 name=\u0022form_token\u0022 value=\u00222CdsORx7q5BQpL5T5KhK40yn1GmYtbzgHnFsU7d5wlU\u0022 \/\u003E\n\u003Cinput type=\u0022hidden\u0022 name=\u0022form_id\u0022 value=\u0022panels_ipe_edit_control_form\u0022 \/\u003E\n\u003C\/div\u003E\u003C\/form\u003E","lockPath":"panels\/ajax\/ipe\/unlock_ipe\/panel_context:page-test:page_test_panel_context"}]

Steps to reproduce:
1. Download Panels and Ctools.
2. Enable Panels IPE and Page manager.
3. Create a custom page that uses In-place Editor.
4. Create a user role that:
- Has the permission: "Use the Panels In-Place Editor ".
- But not the permission: "Change layouts with the Panels In-Place Editor ".
5. Log in as a user with this role and go to the custom page.
6. Now there is two "Customize this page" buttons.