When committing constituent update batchyes, the batch commit hangs for several minutes, then shows a completed status page. However, no records are shown as processed, and the batch is still listed on the Uncommitted Batches tab instead of the Committed Batches tab, with a status of Committing. Even after clicking "Resume," the batch is never committed successfully.
Download and install the latest patch, which contains all fixes from previous patches. If you are running an older version, download and install the latest version and then the patch.