The problem is indeed related to APR::Table, and is as follows:

• APR::Table is a perl interface to the underlying C code in Apache.
• The UTF8 flag (see perlunicode) which marks a string as being UTF8 encoded is internal to Perl
• There is no space in the C code to store the flag

So you generate the string with the UTF8 flag set correctly, put it into APR::Table and it loses its flag. So when you retrieve it, you are receiving the individual bytes rather than the multibye character.

The solution to this is

 
    use Encode;
    my $bytes = get_data_from_APR_TABLE();
    my $characters = decode('utf8',$bytes);
[download]

This way, you reset the flag and all will be happy again.

The issue is that you need to know which strings are UTF8 before you decode them. I find it easier to make sure that everything that comes into my app all gets converted to UTF8, so I'm only ever dealing with one character set internally.