Buy/Trade PUT options in companies going down? Or Bankrupt?

I posted this before and got alot of negative answers saying not a good idea. I opened a DEMO VIRTUAL TRADE ACCOUNT with CBOE-bought Nortel Networks PUTS (various dates) and most have gone up in value in a few days. It seems this would be good to b uy PUTS on companies TRENDING DOWN over 1-5 years? Any Input?