Digital BW, The Print

I am using an Epson 2200 on a PC with WinXP and 2gb of memory.  When
printing an image the first 3/4 to 5/8 prints at normal 1440 speed but
about 3/4 through it slows and the carriage moves with long pauses. 
Near the very end printing speed returns to normal.  This has occurred
previously with no noticeable effect on the print.  

However. tonight I noticed two very thin vertical lines in the area
where the printer slows down.

I would appreciate any comments or advice to remedy this problem.

Thanks,

David Dorn