Linksys WRT54GS SpeedBooster poor performance?

Just got a HP laptop with a Broadcom 802.11b/g WLAN adapter with Afterburner
option. Got a Linksys WRT54GS router to handle the wireless network. Also
have a netgear WGR614v5 router. The problem is, the Linksys with
SpeedBooster is only about half the speed of the Netgear without
SpeedBooster, using a 250 mb file copied from desktop to laptop as a
benchmark. Both routers and laptop are in the same location in the same room
with full signal and 54 Mbps connection. I tried switching channels with the
Linksys with no change in performance. Enabling or disabling the Afterburner
makes no difference either. Linksys has the latest firmware and the Broadcom
is using driver version 3.70.17.0, 6/26/2004 which I think is the latest
available from HP. Any advice would be appreciated.