Microsoft Knowledge Base Article 249256 contains the following summary:
This step-by-step article describes the various symptoms and
resolution methods that you can use to troubleshoot intra-site
replication failure issues.
Important Although Directory Services (DS) replication and File Replication Services (FRS) use the same connection setup mechanisms and replication schedules, they are two completely different components. This article describes common tools and techniques to troubleshoot replication connection objects to diagnose intra-site replication problems.