CCK Multigroup Cache Issue

I am using CCK multigroup (ver 6.x-3.0-alpha4+0-dev) with multistep (ver 6.x-1.5) module. This working fine in the dev server. But in the production server, I getting some issue. When click on "Add more values" button, it returns empty. I debugged that, I found that "form_get_cache" returning empty.

I set #cache = TRUE in the node form, but still getting the issue. Fighting over 4/5 days, have no clue how to fix it. Please somebody help me.

I am using Drupal 6.37.
CCK multigroup - 6.x-3.0-alpha4+0-dev
multistep - 6.x-1.5

Moreover,
-I set field default values for multigroup fields, that default values are not showing.
-Tried to hide None value, automatically displayed when click on "Add more values" button

thanks in advance