Is there a possibility to check, if the DSC1800 has a problem?
Did you do a full factory reset with a reset dongle ?
No, I didn't... What is this "reset dongle"?
See http://lists.gnumonks.org/pipermail/openbsc/2009-August/000804.html
The dongle can be emulated with a carefully placed conductive pin (screwdriver, needed, probe, whatever you have laying around :)
Sylvain