This bug is really simple - you set "<?xml version="1.0" encoding="UTF-8" ?>" (so UTF-8 encoding), but the output is ANSI, which causes some problems when using local letters (like polish "ą" etc.) in computer or domain name.

When encoding of file is set to UTF-8 (which is default), then any special letter is displayed as some garbage, but when I change the encoding manually to ANSI, then all letters are properly displayed.

acct_mgr_request.xml:
<name>Nuwisam</name>
<host_cpid>120268dfd368ffbe7e38d96357e54030</host_cpid>
<domain_name>Bydlڴko</domain_name> (should be <domain_name>Bydlątko</domain_name&gt

Then the error (acct_mgr_reply.xml) is like:
<error>acct_mgr_request empty or corrupt!</error>
<error><![CDATA[Input is not proper UTF-8, indicate encoding !
Bytes: 0xB9 0x74 0x6B 0x6F
.
]]></error>