Multiple problems on Insp 1100

I put in general since we have problems that fit in more than one place.

In an effort to fix/troubleshoot these problems I have formatted and reinstalled XP using the CD shipped with the system, downloaded and istalled the latest firmware and drivers.

1.  Touchpad - unable to enable tap to click,  no amount of checking or unchecking the option, rebooting, uninstalling or reinstalling the drivers will enable it.  I have tried both the touchpad drivers from Dell and the Synaptics site.  Also the touchpad it very jerky, I have adjusted the sensitivity and speed, cleaned, uninstalled /reinstalled drivers/etc. 

2.  When using the machine sometimes a slight bump on the table will cause the screen to turn to garbage and the system to lock up. 

3.  Even after a clean install of XP doing anything (open one instance of IE and browse these forums for example) causes the fans to come on full blast and loud After a couple hours the system will eventually lockup (from the heat, I assume, it gets real hot), doesn't seem to matter if its on a lap or on a desk, been doing this since it was new. 

This is my wife's laptop, third one she has owned (My Latitude C400 is my third as well) so we are familiar with laptops and how they can sometimes get warm, familiar with touchpads, etc.  We have had this machine for almost a year now but are relaizing we should have sent it back and bought a different model.  Is there any possibility of returning this machine for credit toward a different model?  I would have called sooner to get some of the problems fixed (#2 has been a while and #1 just started) but my wife is in college and uses it for her work there so even though it wasn't working well because she couldn't be without it, but now I am contracted to a different company and they have provided me with a laptop for use at home so my wife could borrow mine for a bit.  I would just send it back for repair but we are very disapointed with this machine compared to the other Dell machines we own/have owned, wife HATES this machine now :).  Let me know what my option are here.

Thanks