I'm testing the new Mana Prediction feature with my druid (it's awesome btw!).

When I cast a spell from a shapeshift form using a macro to cancel form immediately:

/cancelform
/cast Healing touch

for a few frames the mana prediction bar is weird, probably due to being applied to the energy/rage bar, which is still visible even though spell cast has begun, and /cancelform has been executed (see below).

a few frames later, when cat form is removed visually and the druid bar disapears the display is ok:

using version 3.047 Beta