You want to delete a single call log / sms log instead of clearing all the logs, right? but there is no way you can achieve this on you phone! This software is for you. You can delete an individual log entry from the log database, and from "Missed Calls", "Received Calls", "Dialled Numbers".
Download :Symbsoft Delete Single Log v1.00(0) S60v3 S60v5 S^3 Unsigned Freeware