Remote AP issue

We have a remote AP that keeps dropping its connection. It is a 924MHz SM feeding a 915MHz AP. We are using a sync cable between them (pins 1,2,3,6). This is at a customers location - both SM and AP are connected to a switch which also connects the customers PC. The SM is dropping from the AP it registers to (a cluster of 3 controlled by a CMM Micro w/GPS). We have tried multiple sync cable configurations, tried without sync cable (which dropped just as much but re-registered quicker), we have seperated the AP and SM by about 25-30ft. , tried different frequencies on both SM and AP, checked ethernet cables and connectors and I am stumped. The strange thing is that this is the stats for the SM when it is connected:

Session Timeout: 0, AirDelay 338 (approximately 9.41 miles (49686 feet))
Session Count: 6, Reg Count 9, Re-Reg Count 10
RSSI (Avg/Last): 1634/1626 Jitter (Avg/Last): 2/2 Power Level (Avg/Last): -61/-62
DnRate(D): 3500 DnLimit(D): 500000 UpRate(D): 3500 UpLimit(D): 500000 (kbit)
LoUpCIR(D): 0 LoDnCIR(D): 0 (kbps)
Rate : VC 25 Rate 1X/1X

Please help - any suggestions will be appreciated.

try a further distance between the two.

I had a 5.2 set up like that and i ended up needing ~50ft

Can you put the SM at 906 and the AP at 924?

We may have to try the 924 and 906 to get the seperation - its just we are shooting into the edge of the coverage are with a 906 from the opposite direction. What is wierd is that we had this problem since it was installed about a week or so ago - then Monday we realized that the AP and SM were too close (site visits reveal a lot of unknown info) so we moved them apart and it was stable (no even one re-reg) for almost exactly 2days then it started again.