I have an Early 2008 MBP 4.1, 2.4Ghz C2D and have no intention of upgrading to Lion for this very reason, Lion is fine on the far faster iCore Mac`s. Both my Air (i5) and MBP 8.2 i7 2.4 breeze Lion with no issues. The last of the "Classic" MacBook Pro`s are best left on Snow Leopard, time to dig out your original OS X disk`s and the Snow Leopard, although the upgrade disk is all you really need, to get the job done 😉