[camz]

I'm a tax accountant and the answer is incredibly simple.

1. File in the state that you incorporated your business. 2. File in the state that you are domiciled in.

The absolute answer to the letter of the law is to file short year returns for California and Mass. because anywhere you were located meant that the company was temporarily based in that state. But, realistically this is stupid and the states aren't going to really care about you because you don't make enough to be worth their time.

So there you have it.