Wireless slow on desktop but not on laptop

I just bought a linksys WRT54G2 wireless router, works fine. Along with that i bought a PCI wireless adapter (WMP54G) for my desktop, but the connection is very slow, sometimes simply off. I don't think the range is the problem, i have a laptop that connects just fine at the same range. I'm wondering if there is some simple change i can make on the wireless settings on the desktop. Btw, I'm pretty new to the wireless networks, figured it would be simple to config, just this petty issue here.

If anyone can help but needs more information, i can add to what i said so far.

Thanks

I have the same issue. I have a PCI card in a desktop and I have 2 dell laptops that came with whatever card they come with. The laptops are fine. The desktop is slow. Funny thing is I have the Super G version of the router and PCI card, so I'm supposed to get 108 MBPS with the desktop and 54 MBPS with the laptops. It's more like I'm getting 2 MBPS with the desktop.

My desktop is on the third floor and my router was in the basement. I moved the router to the second floor. It didn't help at all. I've used the same PCI card in 2 desktops. An XP and a Vista. Both were slow.

I would at least like an explanation of why it's so slow.

I'm thinking of switching to an N network, but everything works fine except for the desktop and I'm not sure if spending $150 and setting everything back up is worth it.