Interesting it tanked in more than one engine. Almost says something about the sites the links point to imo. Have you thought about noindexing it and/or nofollowing the links on it?
I don't like "aggressive nofollow" personally, meaning generally when I link if I don't think the link should be followed I don't add the link, but since the issue with the page is a more widespread drop than Penguin should account for (meaning other SEs are finding something "wrong" too -- maybe one of the linked resources "turned to the black hat side" or something?), so in your case I think I would likely nofollow the page to see what happens and if that didn't clear it up but I still thought it was a good resource for visitors although SEs don't like it, then I would probably noindex it.