if LCDPrint works its safe to say the wiring is correct.... so that is good.
A long shot, but a problem i have had in the past..... when coding my own mp3car programs to use LCD's I have often had to alter the delay times between sending data to the LCD depending on the speed of the CPU running the system.
Faster CPU/system.... longer delay to compensate, otherwise the data is sent too quick for the LCD to make sense of it. Also the length of the cable used. Just last night I was testing my soon-to-be new mp3car system with a 1.5mtr LPT --> LCD test cable I made for development, worked fine with my software. I then tried the 5.5mtr cable to be used in the car (to go from the dash to the boot). The extra length caused alot of troubles, so I needed to increase delays.
As you may/may not have read the length of PC printer cables can never be more than a few meters long or interference starts to be introduced. LCD cable setups are no different.
To cut a very long post to an end..... do any of the plugin you are trying have delay settings? it may be that LCDPrint has a longer delay in its data transfer than some of the other programs you are trying?