What guide are you using... Doesnt sound like any on here. Check mauifrogs 4.3 guide out here
Here is the whole thing that I have now. I need to downgrade my ISO15 in order to change ISO 36, but for 4.3u, I must use TBR 1.14 version. But it always showed exception (DSI) occurred, I really don;t know why this is happened all the time!!!!!! Can any one help me install TBR on my 4.3u?