1. You must have paid Class 1 national insurance contributions on earnings in one of the two tax years before the benefit year in which the jobseeking period began. The earnings must add up to at least 25 times the lower earnings limit for the year.
2. Also, you must have paid, or been credited with, Class 1 national insurance contributions in both of the two tax years immediately before the benefit year in which the jobseeking period began. The earnings or credited contributions must add up to at least 50 times the lower earnings limit for each of the two tax years.
The lower earnings limit for 03-04 tax year was �77 p wk., for 04-05 �79 p. wk., & for 05-06 �82 p. wk. I think (but am not certain) that "benefit year" is not the same as the tax year. Instead it runs from the first Sunday in January to the Saturday before the first Sunday in January the next year.
As you can see, it is somewhat complex. A 3 week gap wouldn't necessarily affect it - it depends on totals for the years concerned.