What kind of data is returned by your callcredit webservice?
Try performing a cfdump on "io".
Also, the cfinvoke/webservice method usually generates the
SOAP wrapper around your webservice arguments. You may want to try
just passing the XML expected by Job5314 (unless, of course, the
method is expecting a full SOAP message as a parameter).
i.e.
<cfsavecontent variable="strpost2">
<pwdchangerequest>
<oldpwd>oldpassword</oldpwd>
<newpwd>newpass</newpwd>
<confirmpwd>newpass</confirmpwd>
</pwdchangerequest>
</cfsavecontent>
<cfinvoke
webservice="
http://localhost/callcredit.wsdl"
method="Job5314"
returnvariable="io">
<cfinvokeargument name="io" value="#strpost2#"/>
</cfinvoke>
<cfdump var="#io#">