It looks like the DDRAM addressing is not the same as the 2x16s. Look in the data sheet http://www.sparkfun.com/datasheets/LCD/GDM2004D.pdf on the bottom of page 8. The lines seem to start at 0x00, 0x40, 0x14, and 0x54.
It looks like the DDRAM addressing is not the same as the 2x16s. Look in the data sheet http://www.sparkfun.com/datasheets/LCD/GDM2004D.pdf on the bottom of page 8. The lines seem to start at 0x00, 0x40, 0x14, and 0x54.