Embedded Passwords
Have you ever spent days pounding your head against a wall investigating an issue that has no logical explanation? Then next time this happens, check for a password embedded in whatever it is you are trying to do.
I just got done troubleshooting a SQL Server Agent job that suddenly stopped working. I talked to our networking and system admin folks, but they couldn't find anything that changed. I validated that the account Agent was running under had the appropriate access rights. Then - on a whim - I decided to look closer at the body of the job. One of the steps had a user name and an encrypted password. As it ends up, that password was changed the day the job started failing.
The moral of this story is - if you do need to embed passwords into jobs or applications - make sure that you document where that password is embedded so that - when someone does need to change it - it can be changed in every place where it is used.