Why does Simplepie return feed items in a wrong order?

I have this feed from picasa (correct but arbitrary, desired order).

The result is messed up

Also, with this feed, for example.

It's fine in regular, sorted by date feeds, but not these. In the object I get from Simplepie it has a messed up order. I don't do anything fancy just loop over the results and display them in the found order using my commercial gallery plugin.

$rss_items = $rss->get_items(0, $rss->get_item_quantity($limit));

I have tried this (hooked into wp_feed_options) but it doesn't change anything: $rss->enable_order_by_date(false);

Also, when I do var_dump($rss_items); I get an array that is represented by 546503 lines of text. I don't believe that's normal, maybe it also hogs the memory, but I can't even look through that data manually to see if the order is inherently bad or just gets mixed up somewhere.

Also I can't tell if it's Simplepie's or WordPress' wrapper's fault.