Ping is not stable (and therefore either the connection). At first I thought the problem was due to a defective product but I quickly realized that the second copy in my possession has the same worries. So I think it's the whole WNA3100M range that is impacted. Netgear forums, many users encounter this problem brownouts but the manufacturer does not seem to react.
Avoid buying this adapter. Your connection will be slow at times and you can not play online properly.