I just took the GRE this past Friday. I did ok on both the Verbal and Quant sections (160 and 165 respectively) but I'm worried about the possibility of a mediocre writing score. A friend of mine, who is an intelligent individual and a fairly good writer, received a 1.5 on writing the first time he took the test despite scoring well in other sections of the test. I feel that since the essays are only scored by one person, there is an inherent possibility that your essays could be considered 'off topic' depending on differences in interpretation of the prompt between you and the essay scorer.
Are these fears unfounded? My scores on the other two sections are fairly average for the programs I'm applying for (Masters of computer science) so I'm hoping I don't receive an abysmal writing score. If my essay scores are lacking however, would I need to retake the entire test and risk scoring lower in the verbal reasoning and quant sections?