OS X 10.4.6 security update overwrites the Windows EFI bootloader.

However, by reblessing the boot partition with the Windows-enabled bootloader, everything is hunky-dory again.

In our opinion, this is not an explicit attempt by Apple to permanently disable Windows dual-booting, but rather, a natural side-effect of applying a comprehensive security update. We believe that the included firmware fix, in particular, may have necessitated overriding the xom.efi bootloader.

For the bleeding-edge crowd that is doing Windows on MacTels, this shouldn't be a biggie.

However, it is unfortunate that the bulletin on the security update makes no mention of this undesired side effect.

We will update this thread as we poke around.