First question: what is your system?
Second question: what is the role of noLoop() and redraw() you mention in the title and not in the message? Why do you use them?

Hi phi.lho. Thanks for taking the time.

I'm very sorry. What specifics of my system did you need?

The program loads and displays large datasets as pixel points. Because it takes a long time to work through all points, I use noLoop() and redraw() to control screen updates only at certain times, occasionally letting loop() run when it's required. I'd be happy to send some/all source if you need it.

Could I just have something borked with Java somewhere? This effect also happens on other people's systems, too, from my compiled source, even during parts where draw() is looping normally (after calling loop())

System = Windows, MacOS, Linux...

noLoop() is rarely needed. For example, if you do a long loop, the screen won't be updated anyway: it is updated only at the end of draw().

Windows XP. Processing 1.5.1
I wasn't sure if you wanted anything more than my OS. :)

If this isn't something you've heard of before, I'll probably assume my Java is screwy. I know I have the latest version, but maybe a complete remove and re-install of Java & Processing is in order..?

EDIT:

I just uninstalled/reinstalled Java as well as downloading a fresh copy of Processing. I exported an application and the exe ran fine! Woohoo! Then I zipped it up to send. Out of curiosity I ran the exported exe again, and, what do you know.. It stops updating the screen again..

I'm thinking perhaps noLoop() has nothing to do with it.

I have uninstalled Java multiple times.
I tried it with 1.2.1 on my system. Same deal. I tried exporting with 1.5.1 on another system. exe appeared to work. Brought it back here, zipped it up. It didn't work on mine, nor on another I sent it to. I have yet to try the same exe back on the system that exported it.

WTH. I'll post my full source if it would help. Anyone?