*sigh* tell me about it. I did pretty well on my GREs (730 verbal [99th percentile], 760 quants [86th]). Just got my AWA scores today and got a 4.5 [58th] after being quite certain I would score at least a 5.0. =\
Admittedly, i took the writing section quite lightly and only wrote a few practice essays, but it was still quite a shock. Am currently re-gathering the will to keep researching the top cog psych programs on my list (am only applying next year).
Ran a google search and this page came up, twas nice to know that i'm not completely alone in this.