Trying to understand PHP6's unicode support

Hello! I am trying to understand how PHP6 handling of unicode works, I think I am missing something. My config is: ;;;;;;;;;;;;;;;;;;;; ; Unicode settings ; ;;;;;;;;;;;;;;;;;;;; unicode.semantics = on unicode.runtime_encoding = iso-8859-1 unicode.script_encoding = iso-8859-1 unicode.output_encoding = utf-8 unicode.from_error_mode = U_INVALID_SUBSTITUTE unicode.from_error_subst_char = 3f unicode.fallback_encoding = iso-8859-1 I use a mysql database, with iso-8859-1 (Portuguese - latin 1) text, with accented characters. What I was trying to understand was, because unicode.runtime_encoding = iso-8859-1, I tought that all internal operations were done in this encoding, and only when outputting (unicode.output_encoding = utf-8) data would be converted to utf-8. So to me, I did a mysql query with latin1, data comes to my variables as iso-8859-1, I use them, and only when I echo'ed them, they would become utf-8, from a iso-8859-1-to-utf-8-like function. But when I do query in any record that have accented characters I get this warning (using mysql_fetch_assoc): ---------- Could not convert binary string to Unicode string (converter UTF-8 failed on bytes (0xE7) at offset 9) ---------- for all accented characters in all fields. The strange thing to me, is the mysql_fetch_assoc function give this error even before I accessed the field values, as I understanded from the above explanation. If I changed the set names query to: mysql_query('set names utf8', $this->mysql_link); then it works, but I would like to understand how this works, to make my program the right way from the start. Did I misundertood something? Thanks, Rangel