GMAT Strategy

Hey All
I am really very confused ....I started with my prep in apr'2008..joined Priceton classroom coaching for 1.5 months....after that with practice of 2 months..i hv improved quite a lot..but now the saturation has come and m not able to improve my scores....
On practice tests;
My scores from the begining:-
PR CAT1 11th March -> 360
PR CAT2 11th Apr -> 460
PR CAT3 17thMay -> 590
PR CAT4 20th May -> 620
GMAt Prep1 29thMay ->600
Manhattan CAT1 -> 600(2 days gap)
PR CAT5 -> 550(2 days gap)............

Why is it happenineg..I dont know.....M not improvin after 620..and now its reversing....is it the stress...or the patience or stamina.....
My date of test was 18th June which i now got changed to 22nd aug...so plz tel me how should i start a fresh..
I have already finished OG 11,OG 10,OG11 quant and verbal review,KAplan 800 premier program....
Wat do i do now..I am out of material.....Where do i study from....when i try to do the same material again...specially in verbal;before reading the whole question;I already have the answer choice in mind as i have done the same question before...PLZZZZZZZZZZZ someone help me out...I am really confused.....I need 700+...plz guys...m ready to cover another book but which one wil be worth....wat should i do

From your post I can see that you have crammed too much stuff in a short time. Your classroom sessions should have been intense by itself. There are a lucky/talented few who get to their target scores very soon, but for others it takes concentrated effort to reach. I would suggest that you do a thorough analysis of the areas you need to improve and focus your efforts accordingly. Taking prep tests without the homework will not take you anywhere. You could definitely reuse the materials particularly the OG11. I am sure you will have something new to learn each time you try the problems. You could continue with the remaining CATs and the second GMAT prep. But remember you should take a test only after you have thoroughly analyzed and taken action on the result of the earlier test. In my experience, this would take more than a week by itself. Wish you good luck.