We have several phones.  They have firmware 7.4.6 when we factory default the phones they correctly pull spa504G.xml from the TFTP server then they pull the spaPHONEMAC.xml from the tftp server and it seems like everything is correct.  But the phone acts up.  Things like the 4 line buttons which are setup as sd+blf+cp flash orange.  The phone randomly reboots when you push any of the digits on the keypad at different times.

The phones work fine if you reset to factory defaults and config them via the web interface.  It is only when they zeroconf themselves with xml files that these issues come in to play.

I have downloaded the xml from a working phone via http://phoneip/admin/spacfg.xml and then used that EXACT xml as spaPHONEMAC.xml and let that upload via TFTP and it breaks the phone as well.

Our system is Asterisk using SIP.

How can I troubleshoot this further?