Making slider update more frequently?

In the VideoOSD slider from estuary:

Code:
<control type="slider">
              ... stuff ...
    <info>Player.Progress</info>
    <action>seek</action>
</control>

I notice that when live TV has been running for a while, seeking around in the slider seeks the TV OK, but the slider position doesn’t update at all, or if it does, it does in large increments. Taking down and re-displaying the OSD doesn’t seem to change it either. I’d obviously like it to accurately reflect the position of the TV/video after the seek.

Questions:
– does the slider position only get updated when the window is first loaded? Or how often?
– is there any way of printing out or otherwise showing the value of Player.Progress to verify that it’s updating?