Help Froyo upgrade wif problems

[htc desire advocate]

I downloaded the froyo upgrade 2 days ago and it seems to have stopped my wifi working. Its not a problem with my router as other devices work on the router. I also checked my desire on other wifi networks and there is no connection to the internet. One of which was at the manchester uk vodaphone store. I manually put in the ip address and the wifi icon comes up but still no link to the internet. When I use my3G mobile internet everything works including my gmail and facebook accounts so it can only be a bug with froyo upgrade. Can anyone help