I have a weird problem and I'm wondering if anyone here have a good idea...

I have a silverstripe installation running just fine, except for one thing : if I try to publish a nested page, I get a javascript parse error

<br />
<b>Fatal error</b>: Maximum execution time of 30 seconds exceeded in <b>/****/sapphire/core/model/SiteTree.php</b> on line <b>1369</b><br />

This happens ONLY for nested pages, top level pages are working just fine. And everything runs fine in my local environment, so I guess it's linked to the webhost somehow, but I don't get why I would have a problem only for nested pages.

Any ideas?

EDIT : updated error code

If i comment these lines (1470 > 1478) it works again

// if(self::nested_urls() && $parent = $this->Parent()) {
// if($controller = ModelAsController::controller_for($parent)) {
// if($controller instanceof Controller && $controller->hasAction($this->URLSegment)) return false;
// }
// }

// if(!self::nested_urls() || !$this->ParentID) {
// if(class_exists($this->URLSegment) && is_subclass_of($this->URLSegment, 'RequestHandler')) return false;
// }