[Blarg]

Clark's post seems sound. Once you have given notice that you might leave, you become more identifiable as a potential future liability. Some companies just think that a guy saying he's thinking about leaving is a bad reflection on the people who hired him, etc. You might get shunted into less desirable or responsible duties, or they may be just waiting for a chance to get rid of you.

That's just idle speculation of course. But I have seen some managers get very angry at anyone who talks about moving on, and develop a real grudge against them. It's not beyond some of that type, perhaps, to keep you on just long enough so that they can be the one to "break up" with you first.

Also, if they pay you more, they may well expect you to work a lot more, to justify the increase. Meaning, some don't feel that an increase is justified unless they thought of it themselves, even if another company proves you are worth more by trying to hire you away. How would you feel about having suddenly raised expectations regarding work hours?