Problem with zbrush group visible please help

Hello Guys;
I have made a model in zbrush and used group visible option to group some parts and saved it to ztool. Later when i load the same ztool model see that all the grouped sections are merged in different ways and positioned differently.

Note: I have same subdiv when saved and opened. Subdiv level is 3.

Please help me to sort out this problem. I googled regarding this problem but dint find a solution.

Please see the attached image

Thanks in advance;