I bought a red LCD from Adafruit last year, to use on a school project. I was following the tutorial, and got to the step where you adjust the contrast and see the 1st row of blocks. Instead of solid blocks, there were gaps in the middle of each block. I continued the tutorial, and got text to display, but missing the middle pixels.
I contacted support, thinking I wad sent a defective LCD. The response was that I should post the problem on the forum in case it was a software issue.
I didn't feel the support option was going anywhere, and I was on a time budget, so I put the LCD in a box and stashed it away. Then I went and bought one that worked and finished the project. I have been cleaning out my storage and found this guy. It would be cool if it really is just user error or a software issue (though I am not sure how 2 grounds, 2 +5v and a pot involve any software...)