Two Possible /castsequence Clipping Problems & Solutions Often Encountered in Multi-Boxing WoW

Why is my stupid channeling spell not working in my /cast or /castsequence ?  It keeps getting interrupted as soon as it starts!   WHAT FOWL CURSE BEFUDDLES ME SO??!?!!!!

The /Assist Channeling Clipping Problem:

If you are experiencing clipping or stopping during channeled move's /castsequence or /cast macro, the reason may be one of the following!:

Question 1:  
Are you doing a channeled move such as mind flay, drain life, etc, and have not heard about [nochanelling]?   If not, precede to question 2.

The Solution To Problem A is:
You'll need to add a simple nochanneling modifier to your cast or cast sequence. An example would be:
/cast [nochanneling] Drain Life. 
 Or:
/castsequence [nochanneling] Vampiric Touch,Mind Blast,Shadow Word: Pain,Mind Flay,Mind Flay,Mind Blast. 
 Leave the brackets

Question 2:
Does your channeling macro contain a /a or /assist?

 It's looking like a classic nochanneling modifier is siting nice and correctly in the coding, and working great.  But suddenly, when assisting someone else, the blue beam of the Mind Flay disappears almost as soon as it becomes into existence.

Let's try to look past the macro and stay focused on the topic.  It  says interrupted, see?!  See!!?

Hopefully what is really happening here is that interface > combat > auto attack on assist happens to be set as on. The cast sequence macro started with a /a (the main assist), and every press of that in this example would make the priest channeling casts break and try to auto attack instead, causing the clipping.

If this is your problem too, you can currently (version 2.4.3) disable attack on assist in the escape menu>interface>combat section as the first option.

Open up the escape menu, click interface

Click on combat on the left to bring up the combat settings pane on the right.  Then un-check attack on assist.  PS: For those multi-box melee drones that you'd like to have at your command, thumbs up for having that option checked.. multi-box dps warriors will be a bit tough to command without it.

If this was your problem, now it is solved, and you may continue on looting your stupid twitching legs for all of eternity.