Serial LCD interfacing problem

Hey all,

I'm working on a Barcode reader. I've got the reader portion working with the PS2 Extended library - it reads the data from the PS2 connection and spits the string out to the serial port. It also prints the string properly to my 2x16 LCD via a Wulfden K107 Serial LCD controller.

When I try to use the setxy(0,0) string to set the cursor location, or any of the "?x" commands, I start getting garbage printed to the display - like my data will print to the proper place, but the rest of the screen will fill with garbage. When I try to write my numeric string I get all garbage. This problem may be specific to my K107 controller, or perhaps I assembled it wrong (the documentation is.. lacking). It boots well and displays things properly until I try to set the cursor position!

Is there some trick to writing to this display that I'm missing?

Update: Ok, so the problem is that the Arduino was firing the setxy event with every new character - I forgot the Arduino reads the my PS2 data character by character. So what I need to do is read the PS2 data into a string, then send the entire string at once with one setxy command. New Problem: The TextString library looks perfect for this purpose, but it throws me an undefined reference when I try to use it. Any thoughts?