After my system has began unstable I have checked its memory using memtest86+ tool. It has found several thousand memory errors. Then I've opened PC case and pulled out the installed 2 DDR2 sticks, blew the dust off, then installed them back. Again, checked the memory using memtest86+ and it haven't found any memory error anymore! I wonder if the dust can cause RAM errors?
It is possible. Dust usually isnt made of materials that can pass current, although its been known to occur. Also, dust can build up an electrostatic charge which can cause issues if its in contact with the memory's connectors.
Also, dust inhibits airflow. Usually it takes a lot, but a buildup of dust can cause the memory to overheat and have errors.
Or, it could just be that the memory wasnt seated properly and when you pulled them out and put them back in, that solved the issue. Sometimes parts just work their way loose...