Digital BW, The Print

I am new to the list and have been benefiting tremendously, although 
much is still over my head. I know that many of you have lots of 
experience with Epson 2200 printers and I have not found an answer to 
my problem on Epson's troubleshooting site. I am using Nanochrome bulk 
feed on an Epson 2200. Recently when I try to print an 8X10 at 2880 
dpi printing begins at normal speed. Then about a third of the way 
through the print the speed slows gradually until printing almost 
stops. I have lots of RAM and no other significant programs running. 
The problem began after a marathon of fiddling with the carts because 
of repeated clogging of the black cart. Then nozzle checks are finally 
okay, but now the printer chokes up as I described above. Any ideas?

Les