I have also been trying to get the BeagleBone working with the Adafruit / Monoprice mini USB wireless adapter (Realtek RTL8192CU). I also have a Belkin F7D1101 USB wireless adapter (Realtek RTL8188SU) and an EDUP EP-MS150ND USB wireless adapter (Ralink RT5370).
The Adafruit is the only one that supports master (soft AP) mode which is what is required for tethering (connman's answer to not supporting ad hoc connections). This is a must-have feature for the application that I'm building the BeagleBone into. So, I was trying really hard to get the Adafruit adapter to work and not go buy another one hoping that the chip set supports master (AP, soft AP, etc.) mode since this information is usually hard to find on distributor and manufacturer websites.
Unfortunately I've seen A LOT of stability issues with BeagleBone / connman / and the Adafruit adapter. I've tried two different powered USB hubs with the Adafruit adapter and it didn't help. Even with line power via the DC jack I had very little success getting the adapter to work at all when connected directly to the BeagleBone USB port.
I've also seen issues where an established connection to an access point is disconnected after a while. Additionally, after deliberately disconnecting from an access point (within a few seconds) the device stops being able to scan for any access points at all until I reboot. I don't know if it's the device or the driver, but it's frustrating to say the least. I have another adapter (ASUS USB-N13 rev B1) with the same chipset on order to help determine if it's the device, the driver, connman, etc..
The Belkin adapter doesn't seem to suffer from the same disconnect problems, but it doesn't support master mode. If Adafruit ends up changing to a different device, make sure it supports master / soft AP mode!