I have an iPod Touch, and I was thinking of finally updating the software both on iTunes and the Touch's firmware.

Will it just be a slight improvement and patch up security problems via Jailbreak, or will it intrude in media and erase anything that wasn't bought in iTunes.

I have several songs and TV shows I've ripped from my purchased CDs and DVDs and then put them into my iPod. I'm worried that the update will erase them. I haven't had this problem before, but I was researching about iOS 4.2 and someone mentioned that they had their entire media erased. Granted he/she had a "Jailbroken" iPod, but I wonder if my stuff will fall into the "non iTunes stuff."