Generally those should be fine, it depends if they are at idle or under load (lots of processing).
It depends on what is what the Computer, Sensor gives a clearer display (for me anyway), as you can see mine are much higher than yours and I don't feel mine are excessive. So I think you can rule out CPU temperatures for the cut out, leaving RAM or PSU.
You can get software to load test RAM and see if it fails, if you have two or more sticks of RAM one could have a problem but providing that is not the one in bank 0 (the first one), errors could be very intermittent.
There is no real way to test a PSU without an electrical test bench/kit. PSUs are very fickle some lasting weeks others lasting years, it is quite possible that the PSU in your system is not a top of the range but a value one (keeps costs down for manufacturers). Mine cost me £75 by Antec.
