Howdy TonyB,
This appears to be a bug in charting when using the Line chart type (right-click the upper chart and hover over Chart Type). The current trading day's price is not plotted in the upper chart (during the week), and Friday's trading price is not plotted if today is Saturday.
However, the lower chart area (Indicator data) is plotted correctly.
This problem does not seem to show up if you use the OHLC or Candlestick chart types.
I'm using PSM version 9.3.1 on Win 7 and had the same bug on my Win XP SP 3 system.
Cheers,
-Don