Blocks on LCD
I posted this comment elsewhere on the forum a few weeks ago. It might help. My display was bright blocks until I replaced the fixed resistors with the pot that came with my display.
My other issue was related to the LCD. After waiting exactly 1 month to get the DealsExtreme delivery from China for the LCD, Arduino, and DDS, I found the LCD had a serial board soldered to all the pin pads. Rather than try to desolder it, I ordered one without the board via Amazon Prime and had it in 2 days. It cost $5.99 rather than $2.39 but was worth it. When I installed and fired it up the display had nothing but bright blocks. I hooked it to an o'scope and made sure the Arduino was talking. I then desoldered the fixed resistors (a little more trouble since they are under the LCD board) and installed the multi-turn 10K pot that came with the LCD. After a few turns of the pot, the display became readable. The LCD literature said it uses LED rather than electroluminescent illumination which may have caused the problem.