Modal Dialog is not blocking Checkboxes and Radio buttons on WinXP

An Application modal dialog is supposed to block all the windows in the application and none of the components in the blocked window must be clickable when the modal dialog is active. But on Mustang, I am able to click and select/deselect the checkbox/radio buttons that are present on a blocked window when the modal dialog is visible. Checkbox triggers an item event when doing so, though the title bar of the frame is grayed out and it remains inactive.

This is reproducible since Mustang-b40 where the new modality changes are introduced. This is reproducible only on Win32 and not on XToolkit. This is not reproducible on Tiger-FCS or Mustang-b36. Hence it is a regression introduced in Mustang and this must be fixed for beta2 since the basic modality feature is broken.

I have attached a sample test. Execute the sample test on Win32. Click on the button. A modal dialog would come up. When the modal dialog is visible, try selecting the checkboxes. If the checkbox gets selected and if you see an item event on the console, the bug is reproduced.
I am able to reproduce the same issue with List also. I am able to select some items from the list when a modal dialog is active. This is also introduced by the new modality changes since it is not reproducible on Mustang-b36.

I have attached a sample test which demonstrates this. Keep clicking on the items in the list and you would see many print dialogs being opened.