RewriteRule ^test\/([a-z]+) test.php?stub=$1 [NC,L]
RewriteRule ^tes\/([a-z]+) test.php?stub=$1 [NC,L]
Is 'test' a reserved word as the second rewrite works fine (on my server) but not the first rewrite.
[edit]Just spent 30 minutes finding that out :([/edit]