Pooling and children removal - qooxdoo

Question

I try to use pooling with my qx.application, because it gives me a significant performance boost on mobile devices (especially Android devices).
For structuring (and for setting huge widget selections to “excluded” with one command) I use many widgets including qx.ui.core.MChildrenHandling.
After leaving a menu I iterate through all containers recursively and add them and their children to a pool.
For object creation I try to get an instance from the pool.
This is working really fine but after some time I get the following error (on Chrome for Android):
“Uncaught HierarchyRequestError: Failed to execute 'appendChild' on 'Node': The new child element contains the parent”
With disposal of the objects, everything runs fine.
This leads me to the conclusion that the objects aren’t always removed from their DOM parent which leads to recursion (a node is added to an old child node of itself).
Can someone point me in right direction how to ensure the removal of the child nodes before pooling them?
Below is the code I use for pooling:
function getPoolElement(type) {
var elem = pool.getObject(type);
//console.log(type.toString() + " " + elem.$$hash + " " + elem.classname);
return elem;
}
function poolElements(container) {
var children = container.removeAll();
for(var i = 0; i < children.length; i++) {
if(children[i].classname == "guibuilder.group"
|| children[i].classname == "guibuilder.picgroup"
|| children[i].classname == "guibuilder.tablegroup"
|| children[i].classname == "guibuilder.bordergroup") {
poolElements(children[i]);
} else if(children[i].classname == "guibuilder.smallchoice"
|| children[i].classname == "guibuilder.choice") {
var opts = children[i].removeAll();
for(var j = 0; j < opts.length; j++) {
pool.poolObject(opts[j]);
//opts[j].dispose();
}
}
pool.poolObject(children[i]);
//children[i].dispose();
}
}
Regards, Johannes