The syslogshold table in the master database contains information about each database's oldest active transaction (if any) and Replication Server truncation point (if any) for the transaction log. This table is built dynamically when you query it.
Check syslogshold for old transactions for the database for which the error occurred:
1> use master 2> go
1> select * from syslogshold 2> where dbid = database_ID 3> go
Determine whether the oldest active transaction can be terminated; it may have been left inactive intentionally. Continue this procedure until there are no other old transactions that can be terminated.
For more information about the syslogshold table, refer to “Backing Up and Restoring User Databases” in the System Administration Guide.