I've always found that the job search becomes much, much harder after you've reached 4-5 years of postdoc. If you aren't successfully interviewing and getting interest by your third year of postdoc, you could be in trouble if you don\'t start getting some action.
I don't know how to advise you on the question you posed about staying too long in the one lab. But going by years, if you are approaching 4 or 5 years, moving now to industry would be a very wise idea.
Employers start talking about applicants being "too academic in nature" once they've postdoc'd too long,
Dave Jensen, Moderator
“I shall tell you a great secret, my friend. Do not wait for the last judgment, it takes place every day.” - Albert Camus