Ok I am have this problem with creatures that I make:

Unless I make every animation start and end at the same "pose" ...there is a noticeable "flickering" in the transition between animations. For example unless idle ends at the same pose that attack starts ... the creature will flicker when it goes from idle to attack.

However I noticed that this problem does not plague Bethesda creatures ... their do not start and end at the same pose ... yet there is no flickering in them.

Can someone explain this please.

What program you use to make your own animations?

Blender ... though for some reason I prefer to use Civ 4 with 3dsmax 8 to export them ...

I was never able to get any animations work flawlessly with Blender. I use 3D Max Studio in whole process and it works quite good.