Anyway, I recently pulled the UX out of storage and installed Windows 8. In so doing, I realized I never posted notes for anyone else who had upgraded the UX to the Intel 5350 Wireless-N card but wanted to use the VAIO Smart Network Utility instead of the VAIO Network Switch Utility.
After trying to remember what I did, I remembered the fix, and so I'm posting this here now for anyone else's benefit (or mine, in the future, when I forget this all again).
Installing the New Utility
First, download version 1.2.00.11260 of the Sony Smart Network Utility from here:
http://esupport.sony.com/US/p/swu-download.pl?mdl=VGNNR260E&upd_id=3348&os_group_id=10
(If you do searches on your own, you'll see that Sony also released version 3.6.0.05180, but that doesn't seem even remotely compatible with the UX)
Second, you'll need to use something like Universal Extractor to extract the installer from the outer Sony wrapper. (Pretty standard process, nowadays, for anyone who has wanted to install non-standard Sony versions/software on the UX).
Fixing the Utility so that WiFi Link 5350 is Recognized
After install, you'll notice that only the Bluetooth control works; it doesn't detect the Wifi adapter. To fix that:
1. Use Task Manager to stop all Smart Network Utility processes (if any are running).
2. Use Explorer to Navigate to "C:\Program Files\Sony\Network Utility"
3. Replace "PluginWlan.plugin" with the file in the ZIP attached to this post.
4. Launch "LANUtil.exe" from the folder, and voila! You should have the option to control WiFi from the Smart Network Utility.
What I did was use a hex editor to modify the hard-coded table of device IDs in the WLAN plug-in. I replaced two of the entries for VEN_8086&DEV_4220 (Intel(R) PRO/Wireless 2200BG Network Connection) with the two entries for the WiFi Link 5350 (VEN_8086&DEV_423A&SUBSYS_10018086 and VEN_8086&DEV_423A&SUBSYS_10068086).
