can any one help??

i have a home patrol. i have the latest data base version,and the latest firmware update. every 2-3 weeks-winston salem /forsyth will dissappear. then in a week or so,will reappear. i checked the freqs. on the scanner,with those on radio reference-all the same-all there. does anyone have a clue.? this is my favorite departments,and it gets irritating after a while. any help will be so much appreciated. thanks