My Today Morning Date Is Interpreted As Part Of Yesterday

OK, the thread's name is not very self explanatory so here I go:

The fact
I'm working on a simple APP where I store the date of a transaction. I use in my Stored Procedure the getdate() as the default (and untouchable) value for the transaction date

The problem:
These transactions are made all day long and there are transctions made on the morning and afternoon. Now, when I make a report of the transactions for one specific range of days, all the transactions made in the morning of the start date are ignored completely.

Say I have these transactions
TCode TType TDate
45 REQ 03/09/2007 08:20:16 a.m.
46 REQ 03/09/2007 11:59:43 a.m.
47 REQ 03/09/2007 12:01:30 p.m.
48 REQ 03/09/2007 06:01:49 p.m.

and I make this query
SELECT * FROM <Table Name> WHERE TDate BETWEEN <Start Date> AND <End Date>
(where <Start Date> && <End Date> are 03/09/2007 selected from a DateTimePicker control)

I only get these results 47 REQ 03/09/2007 12:01:30 p.m.
48 REQ 03/09/2007 06:01:49 p.m.


if I make a cast as integer I get these results:
TCode TDate TCast
46 2007-09-03 11:59:43.000 39326
47 2007-09-03 12:01:30.000 39327


so my question is
Why are the Morning Transactions from the start date ignored (or interpreted as part of previous day transactions) ?