i had same problem as u.....the plastic catch inside the cup holder is broken.....
had it replaced at TCM...cost is $84 for cup holder & labour $60 (waited 2mths for stock to come in)......labour exp cos difficult to take out......but I have learnt how to do so.....
or u can order from online....at
www.japanparts.com......the response by them is fast & good....
or PM me...i can give you the part number.....