ewanspeirs

Hi, i had a Powermaster-10 kit installed about a year ago. Recently the ability arm via a SMS message (arm xxxx) has stopped working. Using SMS to ask the alarms status (status xxxx) works and when use the communications test option via the control pannel i get the Auto test SMS message sent to my phone. I've tried differnet pass codes for differnet users etc. Plenty of credit on the sim card. So all seems to be working except the ability to arm? Any thoughts or suggestions on what else to try/check. Thanks Ewan