Question:
Are you sending data from 1 p/c (notepad ) through the serial port to the PIC and then to a second P/C ? I ask, as today I was working setting up the COM link between a PC and A CNC mill and the serial software by default sends a CR and LF with every line, and you can disable that, maybe your serial program is sending that and the P/C is not expecting it. Just thinking out loud.
JS