Session.LCID changing has no effect

[Just4U]

Hello,

My config : Windows 2003 x64 (US VERSION) + sp2, IIS 6
All regional settings to French (even for default user)
In my ASP pages dates are in the good format (french:dd/mm/yyyy), but
impossible to have US date format when i set the Session.LCID=1033
I did a simple test:
<%
ReturnDateTime 1033, "English (US)"
ReturnDateTime 1036, "French"
ReturnDateTime 2048, "English (UK)"
ReturnDateTime 3081, "English (Australia)"

Sub ReturnDateTime(locale, description)
Session.LCID = locale
Response.Write "<b>" & description & " (LCID = " & locale &
")</b><br>"
Response.Write "Long date: " & FormatDateTime(Date, 1) & "<br>"
Response.Write "Short date: " & FormatDateTime(Date, 2) & "<br>"
Response.Write "<p>" & FormatCurrency(1.05, 2) & "<br>"
Response.Write "<br>" & FormatNumber(1000000,2) & "<br></p>"
End Sub

%>

Results:

English (US) (LCID = 1033)
Long date: Monday 27 August 2007
Short date: 27/08/2007
1,05 €
1 000 000,00

French (LCID = 1036)
Long date: lundi 27 août 2007
Short date: 27/08/2007
1,05 €
1 000 000,00

English (UK) (LCID = 2048)
Long date: lundi 27 août 2007
Short date: 27/08/2007
1,05 €
1 000 000,00

English (Australia) (LCID = 3081)
Long date: Monday, 27 August 2007
Short date: 27/08/2007
$1.05
1,000,000.00

The English US format seems to be ignored.
If i change some settings for the french format (ex:decimal , to .),
changes are applied to the English US format too !!

I tried something else:
I set the server to English US and I apply regional settings to "all
settings to the current user account and to the default user profile".
I reboot and I logon as admin and set my regional settings to French but
NOT for the default user profile.
So i have in regestry hkey_users with English US and hkey_current_user
with French
Now i logon, and test my asp page i have the right values when setting
the Session.LCID.
But it's not a good solution, because i have to logon to get working.
Why it's not possible to get English US format when hkey_users &
hkey_current_user are set to french ?

I'm fed up with this problem.

Any help will be welcome.