[UPDATE: As suddenly as the WiFi stopped working, it started to work again. But I am leaving this question here just in case it happens again. Thanks!]
My Sony Ericsson X8's wifi has stopped working about a few weeks after rooting and installing the GingerDX v030.
Even though it is turned on and scanning, it does not connect to any WiFi.
I have tried rebooting, and also resetting the WiFi antenna (i.e., either by turning it off then on, or by switching to airplane mode and then back out of it).
I have to use the stock kernel otherwise the phone hard bricks.