I've been messing around with the DMR capabilities on my 436 and 536 and I've come across a major issue that's been baffling me: When I enter a DMR system, the scanner will sometimes receive it and sometimes won't. I'll occasionally get a peep out of one, but with one or two exceptions, they'll be quiet. I've played with all sorts of different settings, and I have been unable to put my finger on any one thing that I'm doing wrong. I know these systems are active, but haven't been able to get them to work consistently. I also know I'm well within range of these systems, so reception isn't really the issue.