I blogged earlier about the awesome little ThinkPad X200 I found and its blinking WiFi LED. Briefly I mentioned an odd issue with X/Wayland on LMDE 4. This turned out to be a HW bug that can only be worked around by disabling hardware acceleration for virtualization:

https://forums.lenovo.com/t5/Windows-8-1-8-7-Vista-and-XP-Discussions/Bizarre-screen-artifacts-on-R400-Integrated-Graphics-running-Win-7-RTM/m-p/153980?page=1#199768

The post says it should be sufficient to “Disable Virtualization Technology for Directed-IO (VT-d)", but that didn’t work for me, and I wanted to keep the 8 GiB of RAM I managed to fit into it. What did work, however, was to disable all the virtualization options.