Tax help for military filers

The 6 months deployment was in a combat zone. The W2 is just my military W2. I am assuming that the non-taxable combat pay is just left off the block 1 but accounted for in block 3 and 5. So everything in block 1 is what I made state side in a Reserve status. I read where there were some issues with the military W2s and I was wondering if this was the problem. It just didn't seem correct that I made 70,000 in combat pay (6 months), 15,000 in taxable pay, paid 1500 in taxes but it raised my tax amount due by 2500. So in theory I paid 4000 on 15000 of income for military. The only other issue I could see is if that 15,000 sent me into a higher tax bracket?