gas tank movement

I've noticed something a bit wierd about my 2008 RT lately. I have Moto lights mounted on the lower forks and often look down the steering column to check that I've turned them on since I can see the light in the reflectors mounted on the forks. The other day the lower lobe of the gas tank on the left side had moved in toward the forks so much that I couldn't actually see the light. I pulled over and pulled and pushed on the tank but it seemed firm. On the way home I noticed the lower part of the tank was sometimes about 1.5 " from the forks and at other times it was as close as 1/2" away from the forks. I pulled the fairings off on the left side and the tank is in the mounting lug and doesn't feel loose...just can't figure out whats going on.

Anyone else notice movement of this lower part of the tank on the left? It doesn't seem to matter if its empty or full but does seem to move more as speed increases. I can usually stick three fingers in the space between the forks when parked but it occasionally moves so close to the forks when travelling that I can only fit one finger between.

any ideas?

Ron