Pololu library LCD functions

Hi, I recently bought couple LCD displays of ebay. One is 8x2 and matches nicely with one used on 3Pi and it works like charm. However, second display is 20x4 (from the same company) and it does not work. Connected on the data lines with B2-Orangutan, it does not even show test pattern. When I turn this display AFTER B2 sends init sequence, I can see characters on the display (but obviously wrong, because LCD is probably in 8-bit mode by default). So I know, that display itself is fine.
Can you give me some hints, what can be wrong? I was looking on the source code of the LCD and only tricky part I see is a timing.

Thanks.

You could try slowing things way down and see if that works. The chip on your big LCD could be running slower, or it might take longer to initialize if it has more RAM or something to set up.

- Jan