MemTest86 v.4.3.4. results - assume RAM problem?

[MTSavoie]

I would be grateful if you could confirm that these results do indeed show a RAM error (or if not other possibilities).

For info:
Acer Aspire X1700 - 4GB RAM, 640GB Hdisk, CPU E2200 running Linux Ubuntu 12.10.

Symptoms: system boots (most of the time) but then freezes either at logon or later at random moments. Sometimes system starts and stops repeatedly. Wondered if it was NVidia card related but reinstalled and updated drivers / packages from repository and upgraded from Ubuntu 12.04 LTS to 12.10. Still the same.

[David (PassMark)]

There is a very high probability that it is the RAM.
There is a smaller probability that it is the CPU, motherboard, overheating, EMI or dirty contacts in the RAM slots.

If your 4GB is made up of 2 x 2GB, then try testing 1 stick of RAM at a time.