Well, it seems that the SD agent server is not able to handle the high queue...
There is a difference between the time SD triggered the rule (logserver in SD server), ths is the time that the action was queued in the SMS server, and then the time the SD agent triggered the action (logagent, SMS server).
Service Pack 14 is too old, there are some issues with SD agent that were corected in the Agent in Service Pack 17 & 19.
In the Scheduled Tasks list, in the Actions menu, there is an option to reschedule outdated tasks.
For this to work, the appserver with 2k+ tasks must be down. Then you could reschedule all tasks to the other appserver.
The outdated scheduled tasks will evaluate but will only execute if their conditions still apply but if not, their actions will be ignored and the task should be removed.
Hopefully there's good logic in the DB Rule so they won't execute on items that are not currently relevant.
Another option is to check how many Scheduled Tasks are outdated. If memory serves me right, the OID of the Scheduled Tasks is sequential. If, say, the first 300 Scheduled Tasks are outdated, you could remove those via a DML statement on the rep_javaobjects table. Of course, direct manipulation of the database is not recommended.