In inc_create_forum_sql6.asp there is a line: my_conn.execute ("INSERT INTO CONFIG_NEW (C_VALUE,C_VARIABLE) VALUES ('" & strNewVersion & "' , 'STRVERSION')")
This should read: my_conn.execute ("INSERT INTO " & strTablePrefix & "CONFIG_NEW (C_VALUE,C_VARIABLE) VALUES ('" & strNewVersion & "' , 'STRVERSION')")
You could also replace inc_create_forum_sql6.asp and inc_create_forum_sql7.asp with one version.
I've uploaded a combined version to http://www.btinternet.com/~pweighill/forum/inc_create_forum_sql.zip
This would save a lot of modifying when you bring out new versions of the forum.