Post contents not appearing

Hello. I am having a strange problem for one of my posts. The post appears, but does not have any contents (in either the preview or if I publish). Even stranger, when I make a change and click publish, the post contents disappear from the edit window. If I leave the edit page and then come back to Posts->Edit, the contents are there (until I click the publish button again).

The page contains a simple HTML table – there are no strange table tags. The table is 18 rows, 3 columns, where the third column has little icons (150×150 max). I added the table to the HTML, and it is visible in the Visual editor. I have validated the HTML in a validator (BBEdit) and it was clean.

I have disabled all plugins except Askiment. I have attempted this with both Safari 4/Mac and Firefox3/Mac. It is not a caching issue on the browser, as I am not able to see anything on Firefox when I opened it for the first time. I have attempted to see the post using the default theme, and it does not make a difference.

I don’t believe it is a problem with the browser cache. I was able to add another posting and it shows up, including the content. Because the contents of the edit window disappear after clicking the Update Post button, I was thinking that the WP posting cycle is choking on some part of the HTML, even though it validates (and is very simple (table, tr, td tags)).

The post header (i.e. title) and tags show up, just the body of the post itself is missing.

I have seen no error messages anywhere in the interface during this. Are there any logs from WP that I can look at to see if there is a problem? What about digging into the DB (I think WP saves posts to MySql, not files on the disk)? I am an advanced Unix user, so I don’t might digging in the dirt, but I am fairly new to WP, so I don’t quite know where to look. I’ve searched the WP FAQ, this forum, the troubleshooting guides and was not able to find anyone else with this problem.