I downloaded and installed Leo4all v.2 and it runs OK, so this problem is solved for me
Anyway, thanks br492 for the reply, and thank you roisoft for the 3850 kext, I installed it and it works fine.

Also a big thanks to eddie11c for the Leo4all v2, the only leopard release that runs on my computer so far. My sound isn't working but I'll try to find something for that issue.