It might seem at first to be a good idea but if you
disable ARM the RF management is now manual and you have to adjust each AP individually for optimum coverage. This can be complicated if you do not have site survey capabilities(protocol analyzers, spectrum analyzers) to get a picture of what is happening in the areas covered. The lucent switch
handles this automatically as conditions can always
change in an area covered by the access points. Do you have the option of engaging the vendor support
You might see if there are any code fixes for the Lucent switch or the AP's. If yo have access to documentation there maybe instructions on dealing
with adjusting ARM. While this may not be the case, it appears to be aggresively adjusting to conditions in the environment. This maybe to due a source of intentional or unintentional RF interference and this could be hard to find with out using an analyzer to get a picture of the environment.