Hi. I'm working on this issue right now. I can't reproduce this issue as it's reported.
What can be tricky is maybe this:
Blend1
Tex A ----- Blend2
Tex A ----- Blend3
Tex A
If you want to copy the whole chain, you have to go to the Blend1! If you press copy on level of Blend2, only Blend2 and Blend 3 will be copied. If you press copy while on level of Blend3, only this one level will be copied.
I hope it make sense :)