Problems Regestering

In our initial order, we purchased 20 900MHz SM’s. In our next order, we purchased 50 more. All SM’s have advantage chips with 6.1 firmware.
Our problem is,with our “fringe customers” the older SM’s will regester when the newer ones won’t, both getting the same numbers (1350 RSSI, 3-4 Jitter). I put up a new SM with a flat panel 60 degree antenna, 1275 RSSI 3-4 jitter but wouldn’t regester. I changed the flat panel to a 6 degree YAGI, same numbers but wouldn’t regester. I replaced the new radio with one from our first order and boom same numbers plus immediate regestration. This happened with about 6 customers. Any suggestions?

What’s your AP’s Max Range set at? Check the SMs’ AP Eval page and look for “OutOfRange:0”; if it’s a “1” instead, then bump up the AP’s Max Range.