it doesn't matter if you router is 108mbps or 300mbps if the device receiving is lower than that.
Your Laptop maybe Wireless G (54mbps) so of course it will only say 54mbps
I dunno about the Desktop.
Actually i visited the products Specification page at the Belkin Website and it didn't say anywhere that It supports wireless N which is 108mbps theoretically and less in real.
It just says that its a wireless G 54mbps plus MIMO technology used in the wireless N 108mbps but it's not specified anywhere that it supports the IEEE wireless N standard.
QUOTE
Specifications Standards IEEE 802.11b , IEEE 802.11g , IEEE 802.3u 100Base-T Fast Ethernet , IEEE 802.3u 10Base-T Fast Ethernet
So i my opinion is the router is actually 54mbps.