Animation Cancelling

Well...i am learning XE and there are some simple issues that i can not deal with.

for each spell i always call PolledWait(0.4 - 1) to make it look better...well, they need a small time for the caster to cast, play animation and do the damage, right.?
The problem is..the caster always automatically cancel his animation while the spells are being cast and that looks really weird.

I tried with SetUnitAnimation but it did not work.
Can someone help me?

It's because your unit's cast backswing time is too short for the animation to run through fully. If you want the cast to finish at the end of the animation, match up the two in Art - Animation - Cast Backswing in the object editor. You can see exactly how long the animation lasts by looking at the unit's model and going to the spell animation in that little window to the left.