If i get my offer approved on a house with VA loan....?

We put in an offer on a short sale home and were approved 2 days ago. We were going to put in 15,000 on a down payment and have the rest as a VA loan. But something came up and we wnt be able to put down that kind of down payment. We are approved for 100% coverage. Anyway...do u think the down payment will cause the seller to back out of the deal? I mean...either way the seller will get the full amount?Does the lower down payment affect anything other than our mothly payment? I am so worried this will cause us to lose our dream house....