Web Service Consumer

[IWO]

z/os 1.4, db2 v8

When I try:
SELECT DB2XML.SOAPHTTPV(
'http://www.myserver.com/services/db2sample/ivt.dadx/SOAP',
'http://tempuri.org/db2sample/ivt.dadx',
'<testInstallation xmlns="http://tempuri.org/db2sample/ivt.dadx" />')
FROM SYSIBM.SYSDUMMY1;

I get:

DSNT408I SQLCODE = -430, ERROR: FUNCTION DB2XML.SOAPHTTPV (SPECIFIC NAME
DB2XML.SOAPHTTPVIVO) HAS ABNORMALLY TERMINATED
DSNT418I SQLSTATE = 38503 SQLSTATE RETURN CODE
DSNT415I SQLERRP = DSNX9CAC SQL PROCEDURE DETECTING ERROR
DSNT416I SQLERRD = 0 0 0 -1 0 0 SQL DIAGNOSTIC INFORMATION
DSNT416I SQLERRD = X'00000000' X'00000000' X'00000000' X'FFFFFFFF'
X'00000000' X'00000000' SQL DIAGNOSTIC INFORMATION
DSNE610I NUMBER OF ROWS DISPLAYED IS 0
DSNT408I SQLCODE = -919, ERROR: A ROLLBACK OPERATION IS REQUIRED
DSNT418I SQLSTATE = 56045 SQLSTATE RETURN CODE
DSNT415I SQLERRP = DSNXERT SQL PROCEDURE DETECTING ERROR
DSNT416I SQLERRD = -602 0 0 -1 0 0 SQL DIAGNOSTIC INFORMATION
DSNT416I SQLERRD = X'FFFFFDA6' X'00000000' X'00000000' X'FFFFFFFF'
X'00000000' X'00000000' SQL DIAGNOSTIC INFORMATION

and in wlm adress space:

+DSNX962I DSNX9WLS THE LE/370 CEEPIPI SERVICE RETURNED AN UNEXPECTED
RETURN CODE '00000026'X FOR FUNCTION ADD_ENTRY SSN= DB2P
PROC= DBWLMSW1 ASID= 04DD WLM_ENV= DBWLMSW1

Does anyone have any idea why?

TIA
Ivo