I'm having an issue where a whole lot of iMessages will be randomly deleted back to a random date out of nowhere. This has happened with three different contacts of mine. I thought it might be a BiteSMS issue but they have apparently looked into it and determined it is not a BiteSMS issue. At times it is so bad that I can receive or send a message and it will instantly disappear while I am looking at it in the Messages app. Is anyone else having this problem? A respring stops it when it is happening, but the problem can come back. This has happened about a dozen times now in the past three weeks, with three different people. I have an iPhone 4 with iOS 5.0.1 JBed with Corona on Redsn0w.
Try disabling all your tweaks that may be involved, such as BiteSMS. Some tweaks have bugs that cause some other functions to act strangely or not at all.
Then, re-enable one tweak at a time until you get the bug again. Reinstall the tweak that you just enabled, and hopefully your iPhone should stop the bug.
BiteSMS has already searched their code and said it's not their app causing the problem. I disabled the Messages plugin in Lockinfo and it still did it. I don't have any other tweaks or apps that deal with Messages.
Maybe you should put your iPhone 4 into Safe Mode, and use iMessage with it for a while. If the bug still happens again, this may suggest a corrupted firmware. If it doesn't, than a tweak (dylib) is causing the problem. This way, you can isolate the problem easier