Stacks folder "A" Click > Stacks folder "B" Click > Expansion effect of Object Dock freezes problem
Stacks folder "A" Click > Stacks folder "A" Re Click(Stacks Grid&Fan Window Close) >Stacks folder "B" Click > no problem
This problem solves whether you drag an icon when reboot Object Dock 
Windows 7(32bit)
Object Dock 1.90 Build536
Stacks Doklet 2.0