I also noticed that I was running into similiar issues with my Surface 2, which uses another WLAN adapter (Marvell). This indicates this problem may not be a driver issue for a particular WLAN adapter, but instead a need to change router settings because of issues with RT 8.1. I can't change the RT 8.1 firmware, so I changed my router settings, and so far, so good ... no disconnects.
Based on suggestions in this very long (63 pages so far, so at least my misery has company) thread:
http://answers.microsoft.com/en-us/...i-issues/c593dff8-61b3-496c-b8f2-f9deb3e4b35e
I made the following changes to my router:
2.4 GHz only (no 5 GHz)
B/G only (no N)
Reserved DHCP address for 2520
While so far no disconnects, of course, this "solution", even if it indeed holds up, is not viable in situations in which we don't have control of the router (e.g., work, public). However, it does explain why some are not experiencing problems while others are; different router settings.
For a more global solution, at least until a firmware update addresses this issue, I would like to view the power management settings of the WLAN adapter to make sure it doesn't go to sleep (maximum performance setting). While I can access this setting through the GUI of "real" Windows 8.1, I don't see a way to do so through the GUI of 8.1 RT. There probably is a registry setting but I haven't yet found it.
Hope this helps.