Help! Dell Studio 17 Laptop with Dell Wireless 1510 802.11n Half Mini-Card very, very slow with Linksys WRT54G router.

I was able to get my laptop with an 802.11n mini-card connect to my
Linksys WRT54G router (version 6) without too many issues.

But the download speed on the laptop is limited to 1mbps for some
reason. And usually, I don't even get that. I'll max out at around
35KB/S. Dell's wireless card utility app says the speed limit is at
1mbps for some reason and I looked for some option entry to change
that to 10mpbs.

Is this a speed limit between an 802.11g router and an 802.11n card?
If not, can someone think of somethings for me to check out in the
settings or properties?

The signal strength is always excellent with a full green bar on the
laptop. I have Vista Home Premium SP1 on my laptop and running
Windows XP Pro SP2 on the PC which the router's admin account's on.

I know the sites I'm using to download things are fast because my PC
willl reach my ISP's download speed limit of 10mbps real quick. But
when I try the same with my laptop, it'll top out at around 35 -
40KB/S.

I'm using WPA2 Personal (AES), if that matters at all.

I did go into the laptop's device manager and brought up the
mini-card's properties and looked at the configurable settings, but
there was nothing I spotted which looked to be causing the slow speed
limit.

Any help, suggestions, tips or advice would be greatly appreciated.
Or, is this a case of having an 80211n card connecting with an 802.11g
router?

Thanks for your time and courtesy.