Scale tool becomes Free Transform

Hey!  

If I switch between the "Rotate and Skew Tool" and the "Scale Tool" several times they both start functioning as “Free Transform Tool". I'm unable to lock the scale and resize my bitmap image with quitting and restarting the program. Even after that the "Scale Tool"starts functioning as "Free Transform" after a few uses.

Im not sure if I'm missing a setting or if this is a bug.

Thanks for the help.