Apparently, the latest firmware update for Sony Ericsson's Xperia X10
(which, yes, is still based on Android 1.6
) does more harm than good -- if you're frequently using WiFi and you find yourself in weak cellular coverage, anyhow. Basically, any time your cellular signal drops to zero then bounces back, WiFi turns itself off, which is particularly brutal considering that a weak signal is probably why you're leaning on WiFi in the first place. We don't have details on what X10s are affected, but R2BA026 sounds like the offending version -- so if you see it, we'd probably stay far away until SE manages to push another update.
[Thanks, Sergio M.]