I'm having a weird problem with the Adafruit LCD shield, specifically with the MCP23017 chip sitting on the I2C bus.
My app is in VB
Using the Toolbox driver for this shield
Everything builds fine and starts up well. I get an initial sign on message to display on the LCD and can read the buttons fine. My app periodically writes new data to the LCD (about every 3 seconds or so). At random, the LCD/buttons stop working. My app continues to run fine, but when I attempt to write to the LCD or read the state of the buttons, nothing on the shield works.
I can set breakpoints in my code and everything looks fine -- it executes the Display.Write command to the LCD, but just returns without putting anything on the LCD once it is "locked up".
I suspect a problem with the I2C interface (the only way to recover from this is to power down the board).