We have released a patch file to fix the following problem. This is not a security problems.
The category-based archive is not output to correct path that specified by archive mapping if site has two or more content type.
Please apply patch file. This patch file is available for Movable Type 7.0, 7.0.1.
The patch file contains following files. Please replace the same files on your servers.
lib/MT/ContentPublisher.pm