To add multiple files to a single post, you need to define multiple fields in the configuration panel.
taghaboy’s code should work the same way in 0.6 as it did in earlier versions. (A lot of the bugs in the plugin have been fixed in v0.6 — I recommend all users upgrade).
ddpweb, could you please post the exact code you’re using and the output you’re getting?
The fields are not added as standard custom fields, but as a separate set of fields that can be retrieved with plugin-specific template tags, as documented here:
http://wordpress.org/extend/plugins/nkmimagefield/other_notes/
I’m the author of the plugin. It’s now been tested and verified to work up through WP 2.8.6.
