nodeaccess + cck_field_perms = disaster

I tried to install on my drupal website nodeaccess, in order to block access to certain kind of contents. However, since nodeaccess is very good at managing with all non-cck content types but it doesn't block access to specific cck fields, I uninstalled nodeaccess and installed then cck_filed_perms.
The final result of this was the impossibility to manage correctly users' access: I mean, the admin/user/access way of giving permissions to users didn't work at all.
After dealing with database issues (there is a known bug in the node.module module!) I managed to make all system access work again as it was before installing nodeaccess, but cck_field_perms module isn't working at all.