Howdy.
Sounds like there's some confusion between PS and the colour data in the source file. Photoshop may not be setup correctly to handle the data from your image. Either that, or there's a problem with your RAW data.
You should consider setting up a colour profile inh PS.
Because this can be a lengthy subject, i have to refer you to the PS HELP! files to understand how to set that up. It's fairly well documented so i wouldn't expect you'll have any real problem understanding the instructions.
I'm also not an 'expert' in this area, so hopefully someone who is can chime in here and offer othert suggestions.
Let us know if you still have a problem after doing this.
Hope that helps.