What tolerance the bind system had for serial powers seems to have gone away. I have several bindfiles from the day that did things like toggle on all three shields with one key, and they worked fine.
For whatever reason, any power with an activation time - which is nearly all shields, debuffs etc. - now blocks any others in the string. I can still turn on my tank's shields with one key, but I have to press it three times.
Powers with no activation time still seem to work fine. The "Shields off" button cancels all three with one press.
It's possible the new powexec_location command holds possibilities for chained powers. I'm still experimenting. (See the current "slash commands" thread for the use notes, or the updated Tech Guide, link in the same thread.)