Sahana,
Replication errors and logs are stored with the Replication Agent history.
Go to Replication Monitor on the distributor server using Enterprise MAnager. Expand Publishers and go to the publishing server. Within that branch there will be a list of publications (If you see a red "X" that indicates a problem).
When you open the publications you will get a list of the various agents (snapshot, log reader, distributor). Right-click on the agent and select Agent History. Hopefully you can find the problem by inspecting these logs.
Scott Thornburg
Volt Information Sciences