Hotspot with Wireless disconnects - please help

I have a site where we installed a basic Engenius access point running openmesh - the same setup works fine in over 400 other locations, but not here - beacon stuck.

Anyhow, I switched out the unit with a RB411AR and run hotspot service on it. However, im still having calls from the site saying that the wifi simply does not work - frequent disconnects,

Ive carried out a site scan, and other access points (theres a cisco on site running ch1) works fine. Ive set the distance to indoors,changed the channels (its not that busy RF wise), and frankly am now running out of ideas.

Wireless Config:

name="wlan1" mtu=1500 mac-address=00:0C:42:96:ED:DA arp=enabled 
      interface-type=Atheros AR5212 mode=ap-bridge ssid="WiFiHotSpot" 
      frequency=2472 band=2ghz-b channel-width=20mhz scan-list=default 
      wireless-protocol=802.11 antenna-mode=ant-a wds-mode=disabled 
      wds-default-bridge=none wds-ignore-ssid=no bridge-mode=enabled 
      default-authentication=yes default-forwarding=no default-ap-tx-limit=0 
      default-client-tx-limit=0 hide-ssid=no security-profile=default 
      compression=no

Ive also set HW retries to 4, although cant find where that is hidden in the CLI to post output.

One thing I am seeing is that clients are showing in the registrations table as having a low TX rate (good RX rate) despite having a good signal level of between -40 to -60

Any ideas on how to get a simpel Access Point working!

Any ideas?

Ive fou d a few threads with people having issues like this - someone askes about the antenna a/b setti ga which was causing a low tx rate which had no resolution either.

Could someone share their wireless config suitable for running an internal hotspot in a coffee shop type location (distance settings, hw retries etc) ?

Thank you