For heaven's sake, chaps, do READ LASORS!!
A JAA licence is valid for 5 years.
A SEP Class Rating can only be revalidated by experience BEFORE the expiry date; even if you have 1000 hours in the second 12 month period, if you don't get your Rating re-validated before the expiry date, then you have to RENEW it by LST.
If the FCL150CJAR in your licence was signed by someone who hadn't checked the expiry date, he/she acted unprofessionally and you should challenge him/her on this - ALL Examiners should know the score.
Just do a LST/SPA with a PPL Examiner and your Rating should be renewed without further formality.