TaskDialog doesn't work in 64-bit Take Command

This command in TCC 32-bit (on 64-bit Windows 7) produces the proper TaskDialog

C:\Users\GSchizas>taskdialog ok "One" "Two" Three
The exact same command in TCC 64-bit (same system) does absolutely nothing.

This is probably related to the missing Common Controls dependency in the manifest, as is the flat buttons in config dialogs.