hi Anthony
If you find that you still have some glitches, there are a few other default things that can upset scangun type clients:
1. ARM changing channels too frequently
2. uneven signal due to too much (default) ARM power range as the client roams around, also ARM changing power level too often.
3. CSD (sometimes, varies by model, older devices like 9090 can be affected)
For 1. you can review the ARM history for some of your Aps and see whats going on. if this is a moderate density network, you may have a lot of channel changes due to E or I reasons. Recommend that you split the arm profile into one for 2.4ghz and one for 5ghz.Then, in the 2.4g arm profile we can tweak it a bit to make it less likely to change channel (see below).
For 2., take note of the power that most of your APs are already on for 2.4ghz, make this (for now) the max power for the 2.4ghz arm profile. Make the min power 3dBm less. For the 5ghz arm profile, set the min power 6dBm above the max 2.4ghz power, and set the 5ghz max 3 or 6dB above this.
Example below, comments with # - again, you need to align this to your deployments current values
arm-24g
min-tx-power 6
max-tx-power 9 # align to your network
backoff-time 1800 # may only change channel after 1800
error-rate-threshold 75 # decrease liklihood of ch changes due to errors
error-rate-wait-time 90
!
arm-5g
min-tx-power 15
max-tx-power 18
!
scale these values based on what your APs are currently doing, plus your knowledge of the environment etc.
For 3., go to the "rf ht-radio-profile default-g" and change the setting "CSD Override" to true. Some older clients don't like CSD (cyclic shift diversity) and can benefit from this. The symptom you describe plus replacement of the APs sounds like it could be this.
Try these three for starters, note that the power difference in the ARM profile should help steer a few more clients to 5ghz as well.
regards
-jeff