That happened to me the first time... I needed to install the bootloader manually into my leopard partition by going to /Volumes/SnowOSX/System/Installation/Packages (I think its this, i dont remember very well). After that SnowOSX booted but Leopard stopped to boot :S

So I did a fresh install of SnowOSX without leopard, because I knew Snow Leopard worked :P

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