I am having the same problem with trying to monitor the Aruba Instant AP's. I tried working with tech support but they did not have any prior experience or any documentation on how to monitor these AP's. I would think that when Solarwinds advertises that NPM works with Aruba that they would know how to actually monitor these AP's.
The Solarwinds tech suggested I contact Aruba and get MIBs for the Instant AP and then create a Universal Poller for the AP. I will reply to this post if I figure anything out.
Did anybody figure this out? I need to get a handful of Aruba 105s properly monitored by NPM.