Cannot Request a Java Webservice

[Andrej]

hi,

i have a java webservice which i would like to invoke from .net Application.

i am able to generate the proxy class, but if i try to invoke the webservice
i got an exception of type "java.lang.Null pointer". if i run the webservice
in the debugmode i got an exception:

Message="Tried to invoke method public byte[]
mii.StandardObj ects.DocumentSe curity.WebSigna ture.SignDocume nt(byte[],java.lang.Stri ng,java.lang.St ring,java.lang. String,java.lan g.String,java.l ang.String,java .lang.String,bo olean,java.lang .String)
throws java.lang.Excep tion with arguments
[B,null,null,nul l,null,null,nul l,null,null. The arguments do not match the
signature.; nested exception is: \n\tjava.lang.I llegalArgumentE xception"

the function behind the webservice:

JAVA:
public byte[] SignDocument(by te[] document, String sCredential, String PWD,
String reason, String Location,
String contactInfo,Str ing SigPermissions, boolean LockSignatureFi eld,
String legalAttest) throws Exception

..NET Client invokes the webservice in this way:
sbyte[]
signedDocument= myService.SignD ocument(sbDocum ent,"InvoiceAdm in","password", "reason","loc", "contin","NO_CH ANGES",true,"aa ");

i can post the wsdl if it is neccessary.

please help