I have a BC780xlt and I have all the frequency's of the LTR Trunking in the correct order of channels have trunking on have them set for LT but when I set it to scan does not pick anything up and if I go to manual and go to each channel they work and start reading out ID's. Why won't it work in scan mode? I tried it in my BCD996XT and works fine there. Any Idea's??