We received our tablet on Monday, and initially, I was extremely disappointed. It wouldn't stay online (even though it said it was connected to the internet). When we ran WiFi Checker, it failed at step 4. An hour on the phone with Sony support made it TEMPORARILY better. Had to force some IP addresses, and other (technical) numbers for it to stay connected to our router. NEVER had any issues with any other wireless devices (2 iPhones, 1 Samsung Galaxy, 3 laptops, HTPC, and 1 Bluray player). However, it lost the connection the next day and as soon as it tried reconnecting to the router, it went back to the automatic IP addresses and the problems returned.
Upgraded to ICS (which Sony rep told me would also solve the connection problems). Even after upgrade, still had WiFi issues. Any further than 10-15 feet from the router, and NO DICE. Would constantly drop apps and connections. After upgrade, we also had the Playstore issues (which affected the performance of many other APPS too). A quick google search, and I was able to reinstall the Playstore, and problem was fixed.
Finally, after second call to Sony about the WiFi problems, I did a firmware upgrade on our Netgear router, and it solved the problem! WiFi Checker now passes! Whew!
The only issue now is it still does not have NEAR the reception range as any of our other wireless devices. (Reception is better, but not great at all...) Have to be within about 20-30 feet of the router. Acceptable, but not great. This is not a dealbreaker, but surely Sony could have come up with a better wireless antenna...
After all these issues, I still like the tablet. Just hoping nothing else goes south on it, but only time will tell. Also hoping I don't need to invest any more time in 'fixing' issues. 6-7 hours in the first 2 days is a little much!
My suggestion to those having WiFi connection issues - Try doing a firmware update on your router before throwing in the towel.