Current version of MOC can't be compiled with FLAC 1.1.3 due to API changes in the library. Josh Coalson sent me a patch to fix that some time ago which is included in the SVN repository, but in case someone needs this, it's also here.
Hendrik Iben wrote a modplug plugin which can be downloaded from http://www.tzi.de/~hiben/moc/. It uses libmodplug and supports various formats like .mod, .ux etc. It will be added in the next release (2.5.x line).
I also want to inform that I have a new job which in conjunction with my other activities prevents me from doing MOC development, I don't have enough free time for that :(. It means that you should not expect any new feature-rich release (2.5.0). What I want to do is to fix some bugs that are listed in my TODO file (about 6-10, some are unconfirmed) and make a bugfix version, but even this little release should not be expected soon. This is the moment when you (free software community) can help, if you want a new feature in MOC, don't ask for it, you must do it yourself, the modplug plugin is a good example.
I hope this situation is temporary and MOC development will continue somehow.
I'm sorry to inform that 2.4.0 has a quite big bug that prevents it from playing MPC files and files supported by libsndfile (wave, aiff, etc.). You will also hear noise if you are using a big-endian box (like PPC). This was discovered by Elimar Riesebieter, he tests MOC better than me :). To fix it, you can apply the patch.
I've just received a nice patch from cbass that fixes 2 bugs: searching for directories and moving up and down when using '/' or 'g' (search) command. It is too late to include it in 2.3.2, but you can download the patch from the patches section.