Ok this software is crap if you can't make an installer that works properly. I installed JAI and still get errors saying it needs to be installed. I can tell this software is not written correctly at all or the installer would install everything it needs. What CRAP!
I'm aware of the fact that there are many ways to *NOT* get JAI working. This has been discussed in the forum and summarized in the FAQ. Unfortunately they are not related to the Jomic installer rather then Sun's JAI installer or the way Java is spread across the system (especially if a JDK or multiple Java versions are installed).
I would have liked to make an installer that just works on any platform (like it does under Mac OS X), but the native code of JAI and unrar make this difficult. Essentially it would require to build, test, and release an installer for each platform. As the Mac OS X release is the only one I use myself, it is not going to be me who will implement this. But who knows, maybe the powers of open source will some day yield a solution...
Anyway, the current nightly installer build (and the future version 0.9.25) include JAI as an optional package - without native parts. This causes some bloat, low performance for certain operations (especially reading TIFF images), and needs a hack to prevent JAI from crashing if another version of it was installed locally already. But in the end, it gets you a comic reader for CBZ and PDF out of the box.
It is not all good though because to read CBR you still need to install unrar in the system search path. I'm sorry about that but before blaming Jomic, please read the unrar related questions in the FAQ.