ah yes. I just did a search on 32 vs 64 bits Vista. It seems that another obvious factor at play here would be the requirement of DAW and hardware driver being written as 64-bits applications as well. Is that the case? at least for the common vendors that we come across with recording gears like Motu, Digi design, Presonus or DAWs like Cubase, Protools, Logic, etc?