SLI causing wireless not to work

I have 2x nVidia GeForce 7950GT's and a Broadcom wireless network card. When I enable SLI using the nVidia Control Panel, my wireless connection slows down such that everything keeps timing out, the connection has "Limited or No Activity" and I can't even ping my router any more.

It still "sees" all networks available but is un unable to connect correctly. If I turn of SLI it works fine again, doesn't even need a restart.

I do notice that the wireless card and one of my GPUs share an IRQ.

I have an ASUS A8N-SLI Deluxe mobo with 2GB RAM, the above GPUs and a happy AMD X2 4600 CPU running good old Vista x64.

Any help will be much obliged :-) Thanks