I have had this too and you have to make sure that you have linked out the tamper zone if you havn`t tampered any devices up! That includes the keypad tamper then i would make sure you have the external bell connected right because that also produces tamper lockouts,and then just make sure all your devices are connected up properly! If you have tampered up your devices i.e door contacts or pir`s, the ones you have tampered up you have to make sure they are all seriesed up in the panel! Once all checked you then you disconnect the battery leads and pull the fuse e.g power it down then power back up with the lid tamper spring closed and try that.These bearing in mind are what i have experienced myself and that these you could try!
dean threlfall, February 2008