Slow transfer rate

Hi guys,

After a lot of wireless connectivity issues i finally bought a new PCI adapter that for my rig. I downloaded and installed the latest drivers for my OS (Vista x64) and can connect to internet no problem. However i can only download things at a rate of around 30kb/s. As a comparison, i downloaded the exact same file from the same site using my wired connection and i get a transfer rate of around 600kb/s.

My router is a ZyXEL P-660HW ADSL2+ Wireless Router & USB Adapter
http://www.ebuyer.com/product/109521

My PCI adapter is a D-Link AirPlus-G DWL-G510 Wireless PCI Adapter
http://www.ebuyer.com/product/1032 [...] der_by=RUF

I have tried several drivers for the card both from the Dlink site and the Ralink site (uses RT61 chips) with both giving a similar performance. I have also tried the ZyXel USB adapter (and several different drivers) that came with the router but get a similar performance.

I seem to be getting a decent signal strength (3 to 4 bars) with the router about 5 m away in a different room. This increases to the maximum signal strength (5 bars??) if i move the router to beside the computer, but the download rate doesnt improve.

Are these speeds what i should be getting for this equipment or am i simply missing something. I have reverted back to my wired connection for the time being, but this is going to involve me runing a cable trough several rooms and lifting several carpets to tidy the place up (which is what i was trying to avoid in the first place by going wireless)!!

All help is greatly appreciated as usual, even if it is to confirm that there is no way of increasing the transfer rate.

Rob