Oh, wait a sec...
I just read Brian's reply and he brought up a very good point..
I was assuming that you were using 802.11g with the WRT54GS, but you are using 802.11b?
(My eyeballs didn't pick up the "b" when you described that external card.)
Is the internal wireless hardware 802.11b also? (The way I'm reading your post is that your laptop has internal wireless hardware, which you are seeing these low speeds with and that the external card simply won't work?)
If this internal wireless hardware is also 802.11b, then yeah, that definetly could give you these low speeds.
I have 802.11a, 802.11g, and 802.11b in the air. I'll do a few speed tests (aroundcinci) right now for some comparison:
802.11a: ~ 4.28 Mbs (This is also with DLink's proprietary "turbo". Speed is usually pretty consistent to what I see plugging directly into the cable modem.)
802.11g: ~ 4.07 Mbs (Also with DLink "turbo". Speed is also usually pretty close to being consistent with cable modem, but usually is slightly less than 802.11a. Probably RFI.)
802.11b: ~ 3.41 Mbs (No "turbo", straight 802.11b. This is a seperate SSID from the 802.11g, so to be fair I disabled the 802.11g and put the 802.11b on the same channel,
6, that the 802.11g was on.)
For all of them, signal strength "percentage" ranged from mid 60's to lower
80's, with the 802.11a in the low range and 802.11b in the top range.
802.11a and 802.11g were using WPA-PSK, 802.11b was WEP. I also disabled a couple repeaters I have as well before doing the speed tests. It would've been better to have turned off the "turbo" for the 802.11a and 802.11g before doing the speed tests, but it would've been to config/re-config everything. I don't think the "turbo" makes all that much of a difference for internet traffic though. For WLAN traffic, I see (as Brian also said) maybe a 10 to 20 percent improvent --- even though that DLink icon says "108 Mbs" versus "54 Mbs". Those numbers are just a marketing joke.)
Eric