I have a couple of iMac (10.8 and 10.9), MacBook Pro (10.

Is there any known issues about that ? I know Mavericks has been released yesterday, but maybe i'm not the only one today that got those issues.
I have also try a couple of things:
1) Delete the .timemachine folder through SSH on the QNAP.
2) Disable AFP + TimeMachine options,
3) Tons of reboot both side desktop + QNAP, etc...
So I'm out of ideas here...