DateDiff Function behaves differently on NT under .NET Frameowrk

I have a weird behaviour to report.
I am using DateDiff function to do some date comparison.

Its supposed to throw an error if the input date is less than the current
date.
This happens when the dates compared are 11/11/1111 11:11 and current date.
The date comparison works on Windows 2000 and XP but not on Windows NT. The
same date comparison code works in case the date is say 1/11/2003 09:00, but
not for the above mentioned date.
I do
if DateDiff("n", date1, currentDate) > 0 Then
err
Else
no err
Endif
As you can see I dont hold the difference result in a variable.. so it can
be overflow error..

any ideas

thanks

vidit