i have same problem upgrading from 2.3.6 to 3.0. Log file shows:
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Date: Wed, 24 Jun 2009 10:14:46 +0000
Error Number: 1054
Error: Unknown column 'id' in 'field list'
IP Address: 203.100.254.213
Page: /board/
mySQL query error: SELECT id, name, mgroup, member_login_key, member_login_key_expire, email, restrict_post, view_sigs, view_avs, view_pop, view_img, auto_track,
mod_posts, language, skin, new_msg, show_popup, msg_total, time_offset, posts, joined, last_post, subs_pkg_chosen,
ignored_users, login_anonymous, last_visit, last_activity, dst_in_use, view_prefs, org_perm_id, mgroup_others, temp_ban, sub_end,
has_blog, has_gallery, members_markers, members_editor_choice, members_auto_dst, members_display_name, members_created_remote,
members_cache, members_disable_pm FROM ibf_members WHERE id=1649
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Any ideas?