4.You hate your new boss. In order to work effectively, members of a management team need to have some rapport. Chances are that you took the job - in part - because you were excited to work with the person hiring you. If that person leaves, and his or her replacement possesses characteristics and opinions that are anathema to your own, it may make sense to begin a job search. Perhaps you have thrived in a consensus-driven organization, and your new CEO's command and control approach doesn't work for you. As you spend the time doing your best to nurture the new relationship, you can evaluate new opportunities as they come along.

5.Your industry is failing. It is a courageous move to stay with a company that is dying but cannot reinvent itself to survive. You will gain valuable perspective, build character, and have enough lessons learned to fill a book. Once you've gained all that you can from helping a company try to survive in an industry that isn't making it, you might consider moving to an industry in growth mode. (It's much more fun.)

It is not unusual for a job search to take six months or more, particularly if you have geographic limitations or are targeting a specific industry or narrowly-defined field. If signs point to a less than positive future in your current organization, start your job search now. Ask anyone who has ever put in a disaster recovery plan: It's a lot easier to plan for disaster than recover after it strikes.

Martha Heller is managing director of the IT Leadership Practice at executive recruiting firm ZRG. Reach her at mheller@zrgroup.com