I was actually suggesting you look at your "regular" error log - the one where you would usually find 400, 403, and 404 errors logged. Often you'll find mod_rewrite syntax errors that cause 500-Server Errors listed in there.
About all I can suggest is to try something like this:
Options +FollowSymLinks RewriteEngine on RewriteRule ^([^/]*) /news/index.php?date=$1 [L]
You may also need to explicitly declare a RewriteBase, depending on your server setup: RewriteBase /bosut/public_html
Note that I am "guessing" the rewritebase here - I'd have to see your error log to tell if this is correct, or even necessary. If it is not correct or necessary, it can, in fact, do more harm than good.