Your AWA and IR fall in line with your quant score, and your verbal score is not tragically off. That said, admissions officers are usually more attuned to the composite score. Also, most MBA programs require proficiency in quantitative, while verbal proficiency is less important to them from an admissions/competency perspective.
Keep in mind that the verbal portion of the test tests different skills than the AWA and IR, so you should hone in on what specifically wasn't clicking for you, or whether it might have just been a bad day or slightly tougher than normal section. You'll be the best judge of what isn't working for you. Reflect and correct.
Another common occurrence that leads to a lower verbal score is test fatigue, as it is the last section on the test. Simply maintaining stamina through diet, better sleep hygiene, etc can also go a long way in improving your performance.
Retaking the exam never hurts, but it all depends on what your goals are personally and program-wise. Often, taking the exam a second time will result in improvement simply due to your familiarity with the test, and comfort in having done it once already. Since you are seeking a 640, then the re-take is a foregone conclusion, but you should take care to continue preparing, with special attention to the verbal.
Ben
