hmm... really strange. First time i heard about KP when browsing in Safari. I suspect on something here, for both the cases. What i think is the option to open safe files after downloading is still checked (by defaults) and system is trying to mount downloaded image. It looks like seatbelt is from 10.5.6, from kernel panic. You should install seatbelt and system.kext from 10.5.5 to use them with 9.5.0 kernel. I just think that's the cause.

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