BlackBerry Push Development

[ennova2005]

I have a Push Plus application.  Client app registers succesfully with the PPG .  We are seeing 2 sets of problems

1. Some Devices that were receiving push messages fine stopped getting push messages after a few weeks. The devices were not rebooted nor was the app uninstalled. Does the PPG age out subscriptions?
2. These device appears with status unknown when we query  the PPG using the PAP/BPDS XML apis but were previously getting messages fine per point 1 above.
3. However, couple of other devices that are receiving the push messages fine now do not show up on the list with active status at all. They should not be getting messages if the results of the query are accurate, but are.

See XML being used below.

I am wondering if anyone else has seen a problem where querying the PPG for subscription_query_status returns incomplete information or if there is a known bug in this area. It is difficult to rely on this information if there are inaccuracies in the result.

This query does return a subset of active users - I include the php just to show the XML that is being sent. The results do come back and we recognize the PINs for our enteprise application but not all of them there with active status, even though they are getting the push messages fine.  Others that registered ok are not here and also not getting messages.  This leads me to suspect the integrity of data being returned from this API

        public function setSubsQueryData(){
                if (!$this->appID) {
                        echo 'Please set appID'; return ;
                }
                $this->data = '<?xml version="1.0"?>
                <!DOCTYPE pap PUBLIC "-//WAPFORUM//DTD PAP 2.1//EN" "http://www.
openmobilealliance.org/tech/DTD/pap_2.1.dtd">
                <bpds version="1.0"><subscriptionquery-message pushservice-id="'
.$this->appID.'"><status status-value="active" /></subscriptionquery-message>
                </bpds>' ;