here is another datasheet i found
http://www.ko4bb.com/Manuals/09)_Misc_Test_Equipment/Noritake/Noritake-HD44780.pdf
I found that one last night. It is not a data sheet it is an application note which is valuable, but not the same. If you look at the last page you will find some significant timing differences mentioned which may not be satisfied by the LiquidCrystal (or any other LCD) library. The difference in the Address/data hold time is significant when you consider that the processor can do 11 typical instructions during that 700nS.
Of course you have to speculate on the accuracy of all of the information after you read their description on the previous line concerning what happens on a regular LCD when you write more than 64 (actually 80) bytes of data.
Don