DATE (as distinct to DATETIME) is a relatively new Data Type in MS SQL. As such maybe something in the middle!! is treating it as DATETIME and appending a "midnight" time onto it.
Perhaps some patches / new versions / etc. would make that data-mangling go away?
(DATE is not THAT new ... SQL 2008 I think?? but ... I still find there is loads of legacy stuff lying around that doesn't handle it properly)