via changing the old 1.4 method, which is used in your template $this->getPriceHtml($_item);
and changing the the 1.5 method, $this->getPriceHtml($_item->getProduct());
2 files are below – you really should grep for any other instances.
I was able to fix this error in 1.5, it just doesn’t have any styling. This wasn’t an issue with functionality of top link wishlist. This was an issue with the overall wishlist. The code that is used in your sidebar and view.phtml files had improper call for the 1.5 version of Magento. You may not edit the files for the wishlist, but I can guarantee that the template files for wishlist in your 188.8.131.52 are meant for 1.4.x version and not for 184.108.40.206. Why do you include a wishlist folder in the template install if you just use base wishlist, if it wasn’t there you would have failed back to base template?