4Mb Ram? wow!
I just have 1Gb RAM...
But I'm afraid whatever the bug is, it would consume the whole thing no matter how much resources I add, as it seems the load is only stopped once services (apache/sql) fail.....
And the server is NORMALLY not that busy, which means that in normal conditions, it averages 0.8x to 1.x load averages... Far from the 4.x maximum permitted...