Wait a minute, the pages just before this warning looked fine! How can it run out all at once like that? I smell a rat...
I snooped around online (you KNOW how I love to use the Google machine) and came up with some tips to trick my printer into printing more pages.
Here is the toner snapped into the housing that slides into the front of the machine:
Here it is removed from the housing (why is the photo upside down?)
Pop everything back in place and replace to the front of the printer then press "Go" 7 times (I know it sounds silly, but the "go" part is super important!)
Sit back and print, print, print...
**I'm on about 20 pages so far since I tricked my printer. I'll try to keep track!