iconv can NOT work properly ...

[yes298 yes298]

Dear Sir,

Our company PHP programs developed on Linux, and work normally,
but when move to FreeBSD v7.0(x64), I found that iconv() function can't
work properly,  funciton iconv() and mb_convert_encoding() can convert
gb2312 or big5 to utf8 properly, but can NOT convert between gb2312
and big5, not nothing include error message to show ...

Then I do same testing on FreeBSD with command iconv , also failed
to convert between gb2312 and big5, and error message show:
iconv: cannot convert

Using php function phpinfo() result as below:
iconv support  enabled
iconv implementation  libiconv
iconv library version  1.11

Directive Local Value Master Value
iconv.input_encoding ISO-8859-1 ISO-8859-1
iconv.internal_encoding ISO-8859-1 ISO-8859-1
iconv.output_encoding ISO-8859-1 ISO-8859-1

Using function var_dump(get_extension_funcs("iconv")); to get info as
below:
array(11) { [0]=> string(5) "iconv" [1]=> string(16) "ob_iconv_handler"
[2]=> string(18) "iconv_get_encoding" [3]=> string(18)
"iconv_set_encoding" [4]=> string(12) "iconv_strlen" [5]=> string(12)
"iconv_substr" [6]=> string(12) "iconv_strpos" [7]=> string(13)
"iconv_strrpos" [8]=> string(17) "iconv_mime_encode" [9]=> string(17)
"iconv_mime_decode" [10]=> string(25) "iconv_mime_decode_headers" }

As a result, I found  funciton iconv() and mb_convert_encoding()   and
FreeBSD
command iconv can NOT convert between gb2312 and big5.

Please help to fix this problem, thanks  so much for your help ...

Best rgd,
Victor