Spontaneous change to capitals
I'm working on a document (a novel) which at the moment is just over 100 pages long. I've had no problems in the last few months whatever - until about a week ago. When I loaded the document I found that some apparently random sections of it - sometimes just one para, sometimes four or five pages - have converted themselves to capitals. This now happens almost every time I load the document. And there seems no consistency as to which parts of the document will have changed. This wouldn't be quite so bad if there were then an effective way of changing it back to lower case with initial sentence caps. But the only result I get from using the 'Change Case' feature is for the section(s) which have become all caps change to all lower case. I know this simply means I have to re-capitalize every sentence, but that in itself can be a long and fiddly process. What's happening ? Any suggestions as to how to avoid the change to capitals in the first place?