i put in an sbx 308 with 5 extensions about a year and half ago. they called saying it wont break dialtone at times. i defaulted it but that didnt help. i used nation specific and raised dtmf to acoub about six points. that helped but it still happens about every 30 calls. they get dial tone but from time to time you can dial digit after diget and still have dialtone. seems to happen on all lines and sets. service is now frontier but was verizon. i seemed to be able to break dial every time with my buttset in front of the ksu. any thoughts on this problem. thanks dave