Every subsequent call to an Axis webservice fails

Question

I've been having a strange issue with an Axis webservice which is called through the https protocol.

Basically, when an invocation is made, the call goes through just fine. If the call is made again, the web service fails, returning me with the following message:

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"&gt;
   <soapenv:Body>
      <soapenv:Fault>
         <faultcode>soapenv:Server.userException</faultcode>
         <faultstring>org.xml.sax.SAXParseException: Unexpected end of file after null</faultstring>
         <detail>
            <ns1:hostname xmlns:ns1="http://xml.apache.org/axis/"&gt;f0s0&lt;/ns1:hostname&gt;
         </detail>
      </soapenv:Fault>
   </soapenv:Body>
</soapenv:Envelope>

When tested locally (through http), the service works perfectly fine. Has anyone encountered an issue like this before?

Any help is appreciated.