I answered about your unlock in another thread check that out. If you're on an iPhone 4 and beyond iOS 4.0 then it is not unlockable. You can use BiteSMS to change the tones. You can also change the tones with themes too PM me if you want to do that I find it much better to do it this way. There are others that I've seen but BiteSMS is how I started to do it before I started to write my own themes to do it.
I'm JBen on 4.3.3 and I use Bite without any problems. I'm not saying it's a prob with the JB method but it's an iPhone so if it was me I'd just use one of the other methods to JB. Also instead of using BiteSMS this time just use the theme method I told you about with Winterboard.