PEAR::SOAP and return SOAP_Fault

Hello, I've rewritten a nuSOAP driven SOAP-Server from it's procedural layout to an object orientented code base, using PEAR::SOAP. in my class i've defined some method calls by using __dispatch_map[] and some complextypes using __typedef[] The methods return normal SOAP-Value by for instace "return(String-value);" in the way, i've expected them. But when I want to throw an Error with "return new SOAP_Fault("error message")" the Soapserver runs into nested function calls in Base.php xdebug says: 2--soap_server->service()--/var/www/soap/newsletter.server.php<b>:</b>40</td></tr> 3--soap_server->_sendresponse()--/usr/share/php/SOAP/Server.php<b>:</b>236</td></tr> 4--soap_fault->message()--/usr/share/php/SOAP/Server.php<b>:</b>260</td></tr> 5--soap_base->_makeenvelope()--/usr/share/php/SOAP/Fault.php<b>:</b>79</td></tr> 6--soap_value->serialize()--/usr/share/php/SOAP/Base.php<b>:</b>1005</td></tr> 7--soap_base->_serializevalue()--/usr/share/php/SOAP/Value.php<b>:</b>118</td></tr> 8--soap_value->serialize()--/usr/share/php/SOAP/Base.php<b>:</b>478</td></tr> 9--soap_base->_serializevalue()--/usr/share/php/SOAP/Value.php<b>:</b>118</td></tr> 10--soap_base->_serializevalue()--/usr/share/php/SOAP/Base.php<b>:</b>526</td></tr> 62--soap_base->_serializevalue()--/usr/share/php/SOAP/Base.php<b>:</b>486</td></tr> 63--soap_base->_gettype()--/usr/share/php/SOAP/Base.php<b>:</b>457</td></tr> 64--soap_base->_ishash()--/usr/share/php/SOAP/Base.php<b>:</b>675</td></tr> Is there an other way to throw soap errors? I didn't find anything else about this. Greetings Christian Michel