Redirect error in Group Memberships

After deletion of a membership from copeople/edit, the redirection drops to the index of groups, not back to copeople. There is also a number of index undefined error messages:

2012-09-21 03:17:46 Notice: Notice (8): Undefined index: CoGroupMember in [/Applications/MAMP/htdocs/comanage/registry/trunk/app/Controller/CoGroupMembersController.php, line 331]
Trace:
CoGroupMembersController::performRedirect() - APP/Controller/CoGroupMembersController.php, line 331
StandardController::delete() - APP/Controller/StandardController.php, line 305
CoGroupMembersController::delete() - APP/Controller/CoGroupMembersController.php, line 220
ReflectionMethod::invokeArgs() - [internal], line ??
Controller::invokeAction() - CORE/Cake/Controller/Controller.php, line 473
Dispatcher::_invoke() - CORE/Cake/Routing/Dispatcher.php, line 104
Dispatcher::dispatch() - CORE/Cake/Routing/Dispatcher.php, line 86
[main] - APP/webroot/index.php, line 96

2012-09-21 03:17:46 Notice: Notice (8): Undefined variable: id in [/Applications/MAMP/htdocs/comanage/registry/trunk/app/Controller/CoGroupsController.php, line 172]
Trace:
CoGroupsController::edit() - APP/Controller/CoGroupsController.php, line 172
ReflectionMethod::invokeArgs() - [internal], line ??
Controller::invokeAction() - CORE/Cake/Controller/Controller.php, line 473
Dispatcher::_invoke() - CORE/Cake/Routing/Dispatcher.php, line 104
Dispatcher::dispatch() - CORE/Cake/Routing/Dispatcher.php, line 86
[main] - APP/webroot/index.php, line 96

2012-09-21 03:17:46 Notice: Notice (8): Undefined variable: id in [/Applications/MAMP/htdocs/comanage/registry/trunk/app/Controller/CoGroupsController.php, line 178]
Trace:
CoGroupsController::edit() - APP/Controller/CoGroupsController.php, line 178
ReflectionMethod::invokeArgs() - [internal], line ??
Controller::invokeAction() - CORE/Cake/Controller/Controller.php, line 473
Dispatcher::_invoke() - CORE/Cake/Routing/Dispatcher.php, line 104
Dispatcher::dispatch() - CORE/Cake/Routing/Dispatcher.php, line 86
[main] - APP/webroot/index.php, line 96

...etc.