16.04 LTS crash - frequent and no pattern

ver 14 was stable on my hardware. 16.04 crashes several times per day. There is no pattern: save a file, print a pdf (data was sent to printer), close a FireFox tab, virtual box "send a shutdown signal", copy a file to DropBox, etc Using multiple applications, there is no pattern except it seems to be on BIOS calls. It will work fine for hours then will crash doing the same thing it did successfully multiple times. The AC power is clean (UPS).

It will not save the monitor resolution or placement so these have to be set after every boot (power on or crash) This was ok in 14.1

When it crashes, the monitors instantly go black then it does a normal restart sequence. The crash is instantaneous with no offer to send a bug report. I don't know the "guts" of Linux very well but if there are any log files that might help, I can find them.

64-bit
8GB RAM
Processor: Intel® Core™ i3-3240 CPU @ 3.40GHz × 4
Graphics: Gallium 0.4 on AMD CEDAR (DRM 2.43.0, LLVM 3.8.0)
(Not running Unity)

ATI 4-port video card, 4-monitors (1680 x 1050)
Note: All monitors have to run at the same resolution. I assume this is a driver bug. One is capable of higher resolution but on every crash, it is disabled because the driver can't reload the settings and tries but fails to run it at maximum resolution.