Quote Originally Posted by unit187
Channeled abilities break follow iirc, not 100% sure
tested myself - every ability which turn character (i.e. mindflay or arcane missles) breaks /follow. Channeled spells like Blizzard logically shouldnt break /follow - will test as soon as I get the spell.[/quote]

Some spells break follow and give the 'your too busy to do that' response, though they don't move the character like the warlock drains, mindflay and arcane missles when you try and /follow during them. I believe old school slam is one of these. I wouldn't be surprised if all the channeled spells at times did this because of the tick timing they seem to have. Such as interrupting hellfire seems to not be as responsive as you want at times, but it has a fast tick speed.