Classic siamese behavior question

Question
Karen,
We adopted this cat a little over 3 months ago.  She came from a good loving home, perhaps a spoiled home.  In fact they made the comment to us that this is the cats home we just live here.  They couldn't keep her due to family reasons.  Since the cat was very loving when we visited the cat for the first time, I thought nothing of it.  We adopted the cat and she has been hell on wheels since.  She has adapted to the home, after about a month and doesn't hide anymore.  Now she will hiss for no apparent reason, i.e walking by her.  She will come to me for attention and be purring one minute then hissing and trying to bite the next.  An example, you can be sitting in a chair giving her attention and when you try to get up she will literally try biting you because you are getting up.
We have tried the water bottle trick everytime she hisses, now she just runs from the waterbottle before you have a chance to use it.  Telling her "NO" works sometimes and other times she just looks at you hisses and keeps right on doing whatever she shouldn't be doing.  We have tried the "no attention" bit after her little out bursts and that doesn't seem to bother her.  In fact she gets mad if she wants the attention and you don't give it to her and then starts her evil growling.  
We are completely lost as to what to do.  I can't figure out if she is still trying to fight for her dominance within the household?  If she is doing that, how long before she realizes she would get more love and attetnion if she didn't hiss and bite all the time?  Before this cat, I had my previous cat for 17 years.  Never had these types of issues, he knew his boundaries and when he hissed or growled it was to gain your attention and you knew what his problem was.  It seems like this cat hisses just to be hissing for whatever the reason.

Answer
Hi Brian,

I think you answered part of your problem in the second sentence. You have a spoiled cat on your hands. And a Siamese to boot. You need to find out exactly what the old owners did to spoil her. She most likely is missing that and them. She is directing her anger as aggression onto you.

One thing you can do is not to use negative reinforcement. You see she has already figured how to avoid that. Instead try positive reinforcement. When she comes to you for attention and love give her a treat. When she hisses either ignore her or, if she's on you, blow in her face. Cats hate that. She will not associate you with the air and will start to associate it with her hissing.

See how she is after doing these littles things. And don't forget to find out her special treats at the old home. Good luck and let me know what happens.

Ciao, Karen