I get the following warning on my second site in a multisite install:

user warning: Table 'secprod_d6spimain.node_group' doesn't exist query: SELECT * FROM node_group ORDER BY type_name, weight in /home/secprod/public_html/sites/all/modules/cck/modules/fieldgroup/fieldgroup.module on line 234.

Both sites are running off the same base, the only tables they do not share are:
blocks
boxes
cache
cache_menu
menu_links
variable

Multigroup works fine on the first site where I set the groups up but not on the second site. I tried creating the same groups on the second site and I get all kinds of errors.