Problems with 2009 Kia Optima CHILD SEAT

I learned that some users of the super latch belt on the radian 80sl car seat were experiencing loosening of their latch belts during normal use from sunshine kids juvenile product's facebook page. i went to check my own latch belt and found it to be loose. i tightened it up again and found it very easy to loosen the belt by applying slight pressure with my pointer finger in an outward and downward motion. i also pushed the seat side to side to test the buckle and did not find that it loosened the belt, so it appears to require direct contact with the buckle to loosen it. i've checked the belt every time i've gotten in the car since then and have not found it to be loose since the first time. my car seat sits in the rear facing position and my toddler can easily kick the buckle with his foot and loosen it, which could be devastating if we were to experience a collision while the belt happened to be loose. i contacted sunshine kid's customer service, as instructed by their product announcement, and received a replacement super latch belt for my seat today, 6/9/2011. they have added a retaining clip to the buckle, which does seem to make it more difficult to loosen the belt but i can't say that it works in the car because i have not installed the seat with the new belt yet. i have the original belt and would be happy to provide more information if necessary. i only added a vehicle complaint to provide the vin; i have no complaint with the vehicle itself, only the latch belt of my child restraint. (related vehicle information: model year=2009, make=optima, model=kia). *tr