Driver 340.106-0ubuntu0+gpu1 - occassional blank screen with geforce 210

On an older PC which worked perfectly so far, with i5 760 & 8GB RAM, and NVIDIA Corporation GT216 [GeForce 210] (rev a2) graphic card, Kubuntu 16.04 with standard kernel Linux quox 4.4.0-116-generic, recommended Nvidia driver 340.106-0ubuntu0+gpu1 I’m occasionally (eg no user activity in GUI or login screen, PM screensaver activated, suspend to RAM, resume from RAM, logout & reboot etc) getting blank screen after recent drivers and kernel upgrade.
There is “NVIDIA(GPU-0): Failed to initialize DMA.” in Xorg log.

The OS/Kernel is OK, I can login via ssh over network.

The following line is repeates 1000s of times in kern.log:

kernel: [ 9813.926021] NVRM: Xid (PCI:0000:01:00): 6, PE007e

plus few similar ones, eg

kernel: [ 1231.828871] NVRM: Xid (PCI:0000:01:00): 6, PE0005

This renders the PC box hardly usable.

Any idea what could be wrong?

Also got frozen screen which is not blank some 10 minutes later.
There is following in the Xorg.log:
[ 789.288] [mi] Increasing EQ size to 1024 to prevent dropped events.
[ 789.288] [mi] EQ processing has resumed after 811 dropped events.
[ 789.288] [mi] This may be caused by a misbehaving driver monopolizing the server’s resources.
[ 810.321] (EE) NVIDIA(GPU-0): Failed to initialize DMA.
[ 810.321] (EE) *** Aborting ***
[ 810.321] (EE) NVIDIA(0): Error recovery failed.
[ 810.321] (EE) NVIDIA(0): *** Aborting ***
[ 810.321] (EE)
Fatal server error:
[ 810.321] (EE) Failed to recover from error!
[ 810.321] (EE)
[ 810.321] (EE)
Please consult the The X.Org Foundation support
for help.
[ 810.321] (EE) Please also check the log file at “/var/log/Xorg.0.log” for additional information.
[ 810.321] (EE)
[ 813.322] (WW) NVIDIA(0): WAIT (2, 6, 0x8000, 0xdffe2000, 0x00000014)
[ 820.322] (WW) NVIDIA(0): WAIT (1, 6, 0x8000, 0xdffe2000, 0x00000014)
[ 908.534] (EE) NVIDIA(GPU-0): WAIT: (E, 0, 0x857d)

And similar NVRM prints in kern log as earlier with the blank screen.

What drivere / kerne; version combination is recommended?