Manual Sherline 2000 Mill Axis Lock Troubles

I have a recent (< 1 year) 2000 series mill, and have been having some problems with the axis locks...
Of the three axis locks, only the X-axis seems to work without any issues. Was wondering if anyone else has seen similar issues:

• The Y lock (little thumb knob on the left side of the saddle) doesn't appear to do anything at all. No matter how much I tighten it, I can still easily move the saddle on the Y-axis with the hand-wheel.
• The Z-axis lock (brass lever which tightens the...

Manual Sherline 2000 Mill Axis Lock Troubles