Breaks Magento 1.5.1.0 with "Call to undefined method Mage_Catalog_Helper_Product::initProductLayout()"

[ceefour]

In product page:

http://www.littlestarshop.com/blouse-cewek/orange-lily.html
Fatal error: Call to undefined method Mage_Catalog_Helper_Product::initProductLayout() in /.../includes/src/Mage/Catalog/controllers/ProductController.php on line 67

Kondisi: banyak extension yang terinstall

Percobaan:

1. disable modules output tidak berhasil -> masih error
2. ganti default theme ke blank -> masih error

Solusi: edit app/etc/modules/Soluvas_MagentoTweaks.xml, set /config/modules/Soluvas_MagentoTweaks/active=false