About Non-PNP driver on XP SP2

Dear all,

I experienced a problem with non-pnp driver on XP SP2.
I have a non-pnp driver for a serial smart card reader.
It used to work on XP and XP+SP1.
I used a debug monitor to trace the loading of the driver.
On XP+SP1, I can see the driver loads. Some application (Smart card manager I guess) will then open a handle to it (as I can see debug message from driver’s dispatch_create routine).
Then I install SP2
On XP+SP2 , I can see again see the loads. But I cannot see the debug message from dispatch_create. I guess it is because the application does not open a handle to the driver. I have no idea why doesn’t the application open a handle to the driver as it did when SP2 is not installed !?

Could anyone give me some idea please?

Many Thanks!!
Edward