FW: WAP Push

Hi,
We are trying to use the WAP push implemented via the Kannel PPG gateway in
development version 1.1.6. We are using Hay Systems Limited (www.hsl.uk.com)
for the underlying SMS messaging via SMPP 3.4. In our tests the WAP push
seems to work once in a while, but most of the time the WAP push is not
recieved by the phone. The SMS provider claims that they are delivering the
SMS to the phone everytime and so the message must show up on the phone.
Also the phone has no problem recieving SMS via other interfaces (http) from
the same SMS provider. Does anyone have any clue on what might be going
wrong
Our settings for the SMSC in pushkannel.conf uses system-type = "SMPP"

Thanks
Randeep