Web services passing characters

Hi,

I am consuming a web service that takes parameters

;
"
\
#

but when call the web service it give me errors

Server was unable to read request. ---> There is an error in XML document (9, 53). ---> Input string was not in a correct format.
</soap:Text></soap:Reason><soap:Detail /></soap:Fault></soap:Body></soap:Envelope>


Thanks,

/ZAB