I have been using this laptop for several years without any issues. I am running REW 5.20 beta 8 64-bit with ASIO V2.11 beta 2 on a Windows 10 64-bit laptop using the HDMI interface to my AVR. Here is a description of the sequence of events that reveals the bizarre behavior: 1. I run a typical measurement sweep, say the center channel, 15-20,000Hz, at a measurement level of 90dB. 2. I observe the resulting measurement in the All SPL screen, no smoothing, and it looks perfectly normal. 3. I generate a Waterfall, and everything still looks OK. 4. I switch back to the All SPL screen and when I apply a 1/6 smoothing, the measurement disappears from the screen! 5. When I switch back to the Waterfall screen, the screen is now blank, and the scale on the right now shows -120 to -150dB! 6. I switch back to the All SPL screen, and when I change smoothing back to "No Smoothing", the measurement re-appears. Toggling between No Smoothing, and any other smoothing setting results in the measurement completely disappearing. Re-booting the laptop does not resolve this peculiar issue. I am hoping that some obscure new REW setting is causing this behavior, rather than something wrong with my laptop hardware. If anyone can shed light on what is going on, that would be greatly appreciated. Edit: I should add that when I save the measurements and transfer them to my desktop PC, which is running the same versions of the software, I do not see similar issues.