I'll handle this one..If the stock gets halted for a gap down then your puts will be worth a lot more money. It wont get halted because this stock moves to slow on too much volume IMHO.
Circuit Breaker. A little more detail. When a stock drops hard(see link) Nasdaq does a halt at a certain percentage, to ease the panic and possibly give traders time to assess the situation(my assumption). Later they announce what time it will begin quoting again and when it will resume trading. Your options will also be halted during that time and will not show bid/ask. Its no big deal, happens all the time.