I'm using the following powershift macro:

#showtooltip [form:1]Dire Bear Form;[form:2]Aquatic Form;[form:3]Cat Form;[form:4]Travel Form;[form:5]Flight Form
/dmh start
/use [form:1]!Dire Bear Form;[form:2]!Aquatic Form;[form:3]!Cat Form;[form:4]!Travel Form;[form:5]!Flight Form
/dmh end

This doesn't seem to want to powershift while rooted (via Frost Nova or Entangling Roots, for instance). Is this condition distinguishable from stuns?

After recent client updates, I can no longer reliably reproduce this.