did you ever get an answer to that question?? we too are using MSDTC, but on a single DB (so it's not really distributed), but the MSDTC can wrap all of our .net calls into one transaction. anyways, we wanna upgrade to the Snapshot isolation but appears that the MSDTC (at least with EnterpriseServices) does not support it...
If you got passed your problem, I would love to hear how. thanks!!