So possibly the processes which are running in the background are responsible for that… as I suggested above, this might be related to busy CPU or allocated memory.
If this issue would happen you could check Task Manager which process uses the CPU and memory usage
Maybe this would help to identify the reason for that...
By the way; the Tecra support the TOSHIBA HDD Protection sensor... this sensor stops reading/writing the data on HDD in cases the notebook has been moved... this could lead to short freezings too... disable this for check.