Nokia 5730 firmware issue

[vison]

I have a Nokia 5730 XpressMusic. Recently i update my firmware from nokia website. After that, it always gives me the error:

"Could not connect, WPA-PSK key invalid" 
This key is entered correctly.

My settings in the phone are:
Media: Wireless Lan
Network Status: Public
WLAN network mode: Infrastructure
WLAN security mode: WPA/WPA2
Access points: automatic
The settings in my router are
Security: WPA2 key no Mac address filtering, Open for new equipment and
IP address allocation: automatic. I hope you can help me with this problem. Thanks.

[Snake08]

Firmware is the set in your phone's built software. Occasionally, Nokia firmware updates for certain phone models. If you have problems with your mobile phone, which can be attributed to the firmware of your opinion, please contact your nearest Nokia service center. Find out if a firmware update is available and whether this is included in the warranty for your device.

[Zachary]

For the firmware update it does not need a computer if you have V21 on the phone you can update. As always, it is recommended that before the update a data backup, are with you. The new firmware is the integration of e-mails on standby, also is the menu a bit faster, more changes I could not determine yet if its still what you can discover her write about them here. You just download the original firmware and not chopped. The new firmware 20.0.019 for the Nokia 5730 is released. Update this.

[Big Fish]

The firmware version that you have to told in question that have a software update, but is expected to be available soon. To determine whether the firmware for your phone is already available, you must enter the code * # 0000 # on the virtual keyboard of the 5730 and then choose Options from the point "update". The update will be downloaded directly to your mobile. The new firmware will also be sent by Nokia Software Updater.

[Shen]

Symbian Os have a new firmware for the Nokia N 5730. It may be that Version 31.0.016 not displayed for your smartphone, but then you should make it easy to try again later. The Nokia N5730 has indeed feature "User Data Preservation," but you should still make a backup before you installed the update on your device. Just install the firmware again and look, if what is better there. Flashing back to an older firmware is not that you'd already been to consider and advance the first time properly read into the subject! After the import and production of the firmware updates always first times a reboot of the device and at least one hard reset, perform better, two, then start with other installations.