Older versions of MySQL (prior to 4.1) differed significantly in several ways in their handling of the TIMESTAMP data type from what is supported in MySQL versions 5.5 and newer; these include syntax extensions which are deprecated in MySQL 5.1, and that no longer supported in MySQL 5.5. This can cause problems (including replication failures) when replicating between MySQL Server versions, if you are using columns that are defined using the old TIMESTAMP(N) syntax. See Section 2.11.1.1, “Changes Affecting Upgrades to MySQL 5.5”, for more information about the differences, how they can impact MySQL replication, and what you can do if you encounter such problems.