There is nothing wrong with changing jobs as long as you know what you want to achieve. But you might want to be little careful to keep it minimum.
1. when you make a move, make sure that all your issues/concerns with your current employer are addressed by your prospective employer. It could be your comsensation, your work or your manager(in my case these three have been the reasons all the time). There is no point going from one hell to another hell. Get as much information as possible about your responsibility, your manager's personality, your compensation details and the company's roadmap. Ask questions and do background check.
2. Ask objective questions to your prospective employer e.g. immediately afetr joining what work you would be doing for next two months; if you prove yourself, will you get a change to do work X, Y, Z in next N-months etc. This would also give you an idea about how clear roadmap they have. But finally these all are promises and there is no assurance that these would be fulfilled. Regarding compensation, never consider the variable part of it while making the decision. If you get it, it's bonus.
3. Have a short term goal and a long term goal to achieve in your next company. Once you join a new company, make sure that you achieve your short term goals at any cost over next 2yrs. assess the situation after you have achieved the short term goals. If things are going fine, carry on to achieve your long term goals. Otherwise switch the job. Short term goals are very important as you would like to see youself in a better position in your next company.
The frequent job hoppers, i'm sure you would be bugged by HR professionals about your commitment. Well, commitment can't be unilateral. In one such interview, I was extremely fed up and I told them that my commitment was as good as their commitment and as long as they were committed to fulfill my aspirations, i was commited to stick on to their company. Needless to mention, I didn't get the offer :) Keep it in your mind, but don't express bluntly :)
Finally, any company would like to have a good candidate who has changed ten companies rather than a bad candidate who has stuck to a company for ten years. Good exposure with stability is the perfect combination, but you know life is never so perfect.
