Replace MSSQL by PostgreSQL ?

I have a windows application using a MSSQL (the free 2gig version) database.
When the application is first started, I have to select 'sql server' and
then I need to
give the sql setup (servername, user+pass) in an ODBC datasource setup
dialog.

Now I am wondering, would there be a chance I could use PostgreSQL on my
linux
server, with an ODBC windows driver, and let this application create and use
a postgresql database instead, without having to make changes to the
application
itself?

Or do I have a way to positive idea about ODBC interfaces...

Right now I tried to get this working, I installed postgresql 7.1, and the
postgresql ODBC
driver for windows, but I can't even import database tables from postgresql
in MSAccess.
But this could very well be because the highest version I can select in the
driver is the 6.4/6.5
protocol.

The only way to convince people to move from MSSQL to PostgreSQL would be
when they don't notice the difference ;-)

Should I go on with this, or don't I have a chance?

Best regards,

Pieter