It seems that my laptop wifi connection is much slower than I would expect.  Is it normal or not, and are there are any ways to speed up?

windows task manager shows the wifi connected at 54Mps, but activity is rarely above 3%.  Even when 12" from the router and no slower when 3 rooms away.  If I plug in 100bT cable the speed rockets upto 68% of 100Mpbs.  This is confirmed by the time taken to open large files.  So it isn't a limit in the router, but something with wifi between the router and laptop.  Router is WAG54G.

I'm doing the test by downloading from a network hard disk, not from the internet.  So ADSL speed is not relevant.

I've found the wifi driver settings, Broadcom chipset, and the few parameters of relevance do not make any difference to speed.  e.g. confirmed running in 'g' mode.

Googling on the topic has not come up with any relevant articles unfortunately, but that may be because it's not easy to hone in on this problem when looking for wifi speed.

any comments on what I ought to be expecting would be useful.  Plus any tips on if I can make an improvement.

Thanks in advance.