After a long waiting period finally they released my check on 29th for my last months commision. Was infact planning to contact them if they did not, but finally when i logged in today my payment details showed checque sent on 29th. Is it the same case with you. For how many days is the cheque valid.
I've never noticed an expiry date on my CJ cheques, I'm using DD now, but CJ were usually pretty snappy about postage (to Australia anyway)... I don't think you need to worry about the cheque expiring.