Sharepoint Timer Service complaining about "Attempted to read or write protected memory. This is often an indication that other memory is corrupt." ? It is actually an IIS 6 bug.

Sharepoint superstar Tom Dietz pointed out a helpful hotfix if your Sharepoint/WSS Timer Service keeps throwing errors in the event log. Even though it might seem like bad memory in the server, it is most likely related to KB 946517.

Symptoms include:
Event IDs with 6398, or 6432, or 7076 are logged.
Tasks that are scheduled with the Sharepoint Timer service do not run.

You can read more about it here too.