wireless speed keeps dropping

[amj.designs]

hi,i have been using my router with the sony vaio fj1s/w and i have noticed that the transfer rate between the router and the wireless LAN is always between 36mbps and 48mbps but never the 54mbps.i have contacted the manufacturer of the router not a big difference.i have swapped routers and laptops but still the same.i changed security keys from wep-wap to wap-psk no difference.to add this started when i changed isp,from virgin to talktalk.can someone help please?

[amj.designs]

Hi amj.designs

There is an update for the wireless available here but I don't think this will help your signal strength..

What model wireless router and card do your have..?

safecom SWART2-54125 and intel pro wireless 2200bg