Vista - Wireless button flashing - wifi only working intermittently (HP Pavilion zv5000)

I've upgraded my HP Pavilion zv5000 to Windows Vista, although HP
doesn't support Vista on this laptop.

After I upgraded the display adapter manually (using the Omega
drivers) things were running smoothly - until I wanted to use the wifi
capabilities. The button normally used for switching wifi on and off
doesn't work and the light (on the actual button) that indicates
whether wifi is on or off flashes in a seemingly random manner.

Thus, wifi access is very flaky and it seems that after a while it
just turns off completely, until I reboot.

Any ideas how I can solve this problem. I don't mind if wifi is on
constantly.

Thanks.