I am not sure adding the delay in enable is the right place for your chips? Have a read of this thread from post 25 onwards and let me know what you think
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1210427907/25
This is what I've done. I had to increase the 450ns delay to about 4.5 microseconds to get my LCD from Sure Electronics to work. There seems to be some variations between controllers here. The right controller works fine from about 2 microseconds, the left controller needs 4.5 microseconds.
The example where you modify Enable() does not change the width of the pulse, it adds a longer delay after the pulse. Also, at one point in the code you're generating an Enable pulse without calling Enable(), so modifying Enable() won't suffice.
My LCD needs a 4.5 microsecond pulse with a 4 microsecond delay to function properly.