So, even if your ICAO IR is current, you would have to redo your ATPL ground exams if your JAA IR lapses for more than 7 years.
Haven't you also got to re-do the 55hrs (MEIR) flight training at an FTO, even if you have done it previously and got the JAA CPL/IR?
This 7 year expiry is catching out a lot of airline pilots who went to work outside Europe, and now they cannot come back to work in Europe because of what they have to do to recover their JAA CPL/IRs.