Digital BW, The Print

I hope this turns out to be a very dumb question. I'm trying to set up 
my new Epson 3800. After installing the ink cartridges the set-up 
instructions say the inks will charge. However, at that point with my 
printer the inks don't charge and instead the red light under the "ink" 
symbol comes on and in the message window I get a message that says "No 
Maintenance Cartridge - Install the Maintenance Cartridge SP3800." The 
set-up instructions say nothing about any maintenance cartridge and the 
only reference to such a thing I see in the operating manual is in a 
list of optional accessories on page 11 of the manual. No such 
cartridge was included with the printer that I can see. Could someone 
who has successfully set up a 3800 tell me whether they had to buy 
a "maintenance cartridge" before they could set up and use the printer 
and if not how did you get the ink to charge? Or is there perhaps a 
problem with my particular printer? Or am I just overlooking something 
that should be obvious?