THIS WORKS (at least for me!):
1 - Configure your WPA-PSK(TKIP) network Settings by going to Settings - Connections - WiFi. Or just enable WLAN in the Wireless Manager and when it sees your network put the key in there.
2 - Once Wireless is enabled, let it try to connect for like 5-10 seconds or so.
3 - In the Wireless Manager, while it is trying to connect quickly turn WLAN off and then back on again. Do not let it stay off for more than just a second or so. When it turns back on though WiFi connects to your WPA-PSK network almost immediately.
I've tried this several times now and it works for me. If were to just turn on WLAN and leave it alone, it just sits on "Connecting" and then goes back to "Available" without ever connecting. I've not had to shut off the phone radio or bluetooth or anything - just quickly turn WLAN off and then back on!
I can't take credit for this - I got it from here:
http://forum.ppcgeeks.com/showpost.p...&postcount=442 - its buried 40-some pages into another topic so a lot of people are probably missing it!!