Purple Pitot,
Just to recap your conclusion:
I did my final ATPL ground School exams (NAVs) in february 1999 and passed my CPL/IR in June 1999. Although I have yet to fly my first commercial hour (=I havent found a flying job yet), I have always kept my CPL/IR/ME current. Does this mean that there is no time-limit to unfreeze my frozen ATPL?
That would be great!