In reply to BigBrother:
Working for an insurance company, it would only be a problem if you lied to the company at he beginning of your policy (in which case it could void your insurance) in the majority of cases, the most that might happen is you would be charged a back-dated premium if your job class was a higher risk than the job you were doing at the start of the policy.
Generally though, being unemployed is one of the highest risk categories, so you are likely to be on the right side of the problem. Just don't get a job as a Journalist as they have probably the highest premiums.
Most insurance companies have a way for you to update them of changes in circumstance that don't require a policy change (& charge) if you are concerned.