One more possibility that
may work for some people: local cache. Browsers save a copy of a page on the local drive, and if you're clever you can recover that page. Generally, you will have had to have not been to the thread since it went down for this to work, so it might not apply to most people.
Instructions for Firefox:
IMPORTANT! Before trying to read anything from the cache, click on "File" --> "Work Offline". This will ensure that Firefox reads from the cache and doesn't try to "update" from the website.
Type "about:cache" into the address bar. This will bring up a page all about your cache.

Explore and see if you can find the pages you're missing. Try doing a Find (CTL-F) for "www.enworld.org/showthread.php". When you find one, click on it. If you haven't been to that page since the crash, it should have the missing posts in it. Save the page.
For those of you running PbP games, ask your players to try this, as one of them may have something you don't.