I just updated to version 188.8.131.52 for my 3406B. Now when I zoom in, display does not update the waveform when scrolling left or right if zoomed in. To recreate, do the following:
Trigger: Repeat, some channel with a probe, level 1 volt
Zoom in to some level (I was using x64).
Sweep rate is not important, for test set to 1 ms/div.
Get a waveform on the screen from a single event, easy to do by just touching the probe tip with your finger.
NOTE: Do not hit stop! The display will be static du to no triggers coming in.
Scroll the display left or right.
During the scroll, the waveform display that is scrolling into the window is blank.
If I hit the STOP button, then waveforms update OK. This problem occurs when the trigger is armed, and waiting for a new trace, and you are looking at an existing trace.