How do I move a category to another category with all child categories?

I have tried the following solution:

```
$nodeId = 2269;
$parentId = 2268;

$tree = Mage::getResourceModel('catalog/category_tree')->load();
$node = $tree->getNodeById($nodeId);
$parentNode = $tree->getNodeById($parentId);

$parentChildren = explode(',', $parentNode->getChildren());
$afterId = array_pop($parentChildren);
$prevNode = $tree->getNodeById($afterId);
if (!$prevNode || !$prevNode->getId()) {
    $prevNode = null;
}

$tree->move($node, $parentNode, $prevNode);

```

However my result is somewhat twisted. If I move to the root-category the move works, but if I move to a child-category I get faulty results and disappearing categories.

These are the values of the field path in the database:

```
Old: 1/2/3/2175/2269
New: 1/2/3/2175/2226/2268/2269
Correct: 1/2/3/2226/2268/2269

```