binary_checksum craziness

Folks, hi.
Any idea why this patently different items return the same binary_checksum value:

select
binary_checksum('X', convert(datetime,'2006-13-12'), convert(datetime,'2007-17-04'), convert(datetime, null),'X','X','X','X','X','S','X') [1],

binary_checksum('X', convert(datetime, '2006-28-11'), convert(datetime,'2007-17-04'), convert(datetime, null),'X','X','X','X','X','B','X') [2]

The core of a very major system is based on these computing unique values for a unique set of expressions!Because BINARY_CHECKSUM is not guaranteed to be unique. From BOL:

BINARY_CHECKSUM(*), computed on any row of a table, returns the same value as long the row is not subsequently modified. BINARY_CHECKSUM(*) will return a different value for most, but not all, changes to the row, and can be used to detect most row modifications.|||The core of a very major system is based on these computing unique values for a unique set of expressions!
Oops. Somebody should have done some research first, eh?|||Oops. Somebody should have done some research first, eh?

At the risk of overstepping my bounds: don't be an anacedent.

Regards,

hmscott|||Point taken...|||A most helpful forum indeed it has to be said.|||Here is how CHECKSUM is calculated. You can see for yourself how Microsoft do and why many checksums are the same.

http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=70832|||Thanks Peso.sql