OK, a followup on whats going on:
I posted on the linux-dell-laptops Yahoo! group and I found that pressing Fn+F7 (the 'Font' key on the Inspiron 4000) to switch it into 1400 mode before exiting solves the problem. Seems great for a temporary remedy, but I'm still going to be looking for a more permanent solution.
BTW, downgrading to 4.0.1 still yields the same results. Maybe it's just me...