http://bugs.winehq.org/show_bug.cgi?id=56391
--- Comment #9 from imaxm memax@gmx.fr --- Looking at bug 58751, it appears that WineHQ binary packages for Debian/Ubuntu were provided without ntsync.
That said, I haven't been able to build Wine with ntsync enabled. Configure gives me 'checking for linux/ntsync.h... no' even though the kernel comes with ntsync and the module is indeed loaded.