Just got back from taking my GMAT... ugh.back to studying

I just got back from my test this morning. I scored a 590. I was hoping for 650. I took the KAPLAN gmat course and studied for about 10 weeks almost everyday. I had looked into the GMAT before so I wasn't starting from scratch. I was hoping to do much better. I had been scoring in the 580 - 610 range on 4 practice tests. The practice tests were timed and included the essays. I was hoping on test day I would be more focused. I felt good on the math but started to run out of time for the last 10 questions, I thought I was good until then. I had a difficult mixing problem that I thought I got right around question #34 but then question #35 was an easy average question, so I got concerned. I was normally scoring in the 51% percentile but I only scored in the 39th percentile during my test. My verbal felt good but I only scored in the 78th percentile.
My averages were:

Last 4 practice tests:

590: 40% Quant, 81% Verbal - first test taken - {had taken 3 prior scoring 570}
590; 51% QUANT, 66% Verbal
610; 51% QUANT, 66% Verbal
580; 51% Quant, 56% Verbal - last test taken

GMAT: 07/09/2010
590; 39% QUANT, 78% Verbal

I am happy to read on these forums people have taken multiple tests. I am trying to get into NYU. Any suggestions on what I could have done different? I am hoping to take it in a month but my Kaplan course runs out and now Im on my own.