rdesktop 64-bit fails with SmartCards

Issue

• A USB-attached SmartCard reader is recognized by the OS, but the token is not recognized in the rdesktop session.
• The target of the rdesktop session is a virtual machine running Windows 7. The Windows 7 client does see activity when the device is connected or detached, and when a card is inserted or removed, but fails to recognize the token on the card, stating "No valid certificates found".
• A 32-bit rdesktop binary works correctly, but not a 64-bit rdesktop.