What is wrong with my African Dwarf Frog?!?!?!?

I bought an ADF just over a week ago and he is in a 10 gallon tank with a couple of mollies and guppies. they have all been fine together and he has been fine until today. This morning i saw him floating upside down so i umed he was dead so i scooped him out of the water with a net and he started kicking and climbing on the net, so i put him back in the water and he went back to floating upside down at the top of the tank. I have checked him all throughout the day and he seems dead but if i touch him or scoop him with the net he kicks and squirms and climbs on the net and stuff but as soon as i put him back in the water he goes back to floating upside down!!! HELP!!!!!!