iPhone Search does not find historic SMS messages On my iPhone 4, I have a large number of SMS messages (I don't delete them at all).

If I want to search for text in a particular message, it appears not to search historic SMSes. In other words, unless the text is visible in the latest messages, viewable on the screen without tapping "Load Earlier Messages", it will not match my string.

Am I doing it wrong? Is this a known issue?
Apple does not search for very old text messages as it makes the search much slower. There is no setting to modify the period of messages it should go through, but if you really need this then you can jailbreak and SSH into your iPhone. You can then edit the .plist file and make it search for messages that are even 2 years old.

Note: This will significantly make the searching slow.