Last week I used the bed in my truck to transport some light materials. It opened and closed ok when I loaded the materials, then it opened ok when I unloaded. The only thing different I did this time was stand on the tailgate getting into the back. I weigh approx. 215lbs. The gate closed ok and I did not try and put the gate down again until yesterday. When i went to pull the release, nothing. Like pulling at air. Its frozen. Any ideas.....?