Optimize Error

Hi
I keep get errors evrey time I add / edit / order a root node
If it is a nest node it is all looks fine
but when it is a node in the root level.
I keep geeting this errors on the function _optimize_orders
that the parentPosition variable is undefined,
than It is maiking the process.

Any Idea
Best Regards.
Thank you All

if(count($PositionS) > 0) {
$parentPosition = implode(">", $PositionS).">";
}

Root nodes are not > 0, so the $parentPosition is not defined!

I don't know if it's solved, but i added this:

else {
$parentPosition = "";
}

At least the error is gone...