Radio hold-off timeouts occur when the radio is trying to transmit data but is unable to due to the fact that it perceives that there is other data traffic going on i.e. a extremely busy rf network, however i have experienced these hold-off timeouts when there has been interference from appliances which are allowed to use the 2.4GHz band. i.e. burgular alarms/fire alarms etc.You can carry out a diagnostics test on the Access Point which will give you a pretty good indication of your traffic/interference levels. This can be accessed through your main menu/diagnostics/radio diagnostics tests/carrier test. N.B. carry out this test either through the serial port or LAN side. good luck