This is more of an oddity than a problem for me. I am using 12.0.4 LTS and have hfsprogs installed. (I don't have any reputation so I can't create a tag for hfsprogs, and that it doesn't already exist ...
This is a recurring problem and occurs a few times a week. I have an external hard drive which is hfs+. Every couple of weeks, for no obviuous reason, when I mount it by pluggin it in to my Ubuntu ...