Do a search on ATI video cards on this forum...and feel the "love":(
I booted my live CD on a number of laptops at Best Buy (I was fortunate to get a salesman who was a linux nut). One Compaq model went straight to windows no matter what was done in the BIOS. (Odd, since I am using Compaq now) A Gateway I tried acted much as you describe. One series of Toshibas did everything perfect. I was a Satellite A205-54577 on sale for $749. PERFECTION! The sales dude even confirmed that the wireless card worked with terminal commands. This guy was WAY TO SMART to be working at Best Buy.
He says (as a Gentoo fan who builds everything from source, yuck) that Toshibas generally work most reliably, BUT, you damn near have to load the live CD and run a few commands [ lspci is one that comes to mind ] to find out what kind of hardware is onboard. As a generality, Intel hardware usually works. ATI and Broadcom, not so much.
Bear in mind that I am a recent convert to Ubuntu, and by no means a guru, but maybe its easier to switch than fight.
With Dells starting at $599 and this bitchin' toshiba going for $749 (1g, duo, 160g HDD, 15.4 screen), maybe its time to consider putting your Inspiron on eBay. Laptops fetch good prices on the used market. Freshmen college students come into the market strong this time of year.
That's what I'm going to do anyway.