as you probably remember, I am also a happy Studio One User. I never had any problems with Studio One and my very old Terratec EWX 24/96 PCI soundcard, first on Win XP and since August this year on WIN 7 64bit, even though I am using old VISTA drivers, since Terratec doesnt feel the need to support their older products anymore (contrary to M-Audio's Delta Audiophile 24/96, which also came out around 2001..., but sorry I digress).
Long story short: I bought Reason Essentials two weeks ago and it is actually the first piece of audio software which wont work at all with my old Terratec, so now I am forced to buy a new soundcard and I was thinking: Focusrite Scarlett 2i2.
I am actually planning to get it within the next few days, so hopefully I will be able to give you some feedback at the end of the week. Until then, I think I remember Russell Bell getting the Scarlett 2i2 lately, so hopefully he'll read this and have some advice for you.
I'd love to try the Presonus Audioboxes, too, but the Audiobox in the comparable price range only goes up to 48kHz.
Hope you get that problem resolved quickly. Fingers crossed! Cheers!