I would definitely go with the old company, unless you are under some sort of crippling debt. The old company cared enough about you to help you find work when they had none for you. In my non-expert opinion I would think that would be a better company to work for because while the pay may be less in the short term, you have way better job security, and I'd also bet working conditions there are better because you probably get to work with cooler people etc.
Plus working for big corporations sucks. Everyone is worried about corporate bullshit. I know it's probably not the same really, but I work at a small coffee shop and have friends that work for starbucks and goddamn. I'm glad I don't have to put up with the shit they do.
Oh yea and that small company will eventually grow so you have a better chance to move to a higher position I would think.