I may not be understanding your issue but if all you are doing is changing kernels you shouldn't be doing a wipe. Just use ROM manager to install rom from SD card. The new kernel zip file should be on the root of your SD card. Choose the kernel you want to try and install but do not wipe. For going back to the original kernel you will need to do a restore of your backup unless someone can direct you to a zip file of just the original kernel. I know it's been asked here on the forum for the original BB kernel to be posted but I don't see where that has been done. It would save having to do full restore if the tested kernel didn't work out. Hope this helps.