Primary reason is speed I suppose. WinIO has been faster than DLPortIO when I've tested.
I posted some results here:
http://www.skippari.net/phpBB2/viewtopic.php?t=142
Also WinIO haven't really caused me any problems and DLPortIO once just stopped working in my system (when trying to run older LCDInfo or LiQuiD-MP3 there was just the error message saying that port driver wasn't loaded) and I wasn't able to fix that. I've heard of similar problems with DLPortIO from others too but never with WinIO.
I have noticed some differences between the two. WinIO being faster is one of course. Also there have been reports that same display driver code compiled using WinIO or DLPortIO has differences in how well it works in different systems. Timing differences I suppose.
The reason you're seeing what you reported might be that LCDInfo and LiQuiD-MP3 have different timing for Noritake 800.
Without further testing I'm not able to comment to the issue about reading from parallel port...